Missing Primarchs (40K)

[Irbis]

There are hostile aliens. The Imperium kills them. There are neutral aliens. The Imperium kills them. There are friendly aliens. The Imperium kills them and conquers the humans who get along with them. This continues way past the point where the Imperium is just Terra and Mars trying to forge some sort of order out of a cosmos that has been abusing humanity. Once the Imperium becomes more secure (by Ullanor at least), a policy of xenocide stops being self defense and becomes a waste of resources.

One problem with that argument - Warhammer aliens are not SW or ST aliens. Quite a lot of them are stuck on permanently hostile mode, even if they look peaceful from time to time. Some races are nothing more than walking weapons, leftover from the time of War in Heaven. Things like Hrud, Orks, Tyranids, hell, even Eldar are nothing more but walking guns given flesh and intelligence. Exterminating them on sight is saving resources in the long run.

As for really peaceful aliens? These do exist, and are often not exterminated. You're aware Inquisition has both diplomatic branch and xenolinguistic branch? These exist for a reason. Granted, in many cases it's just 'really low on list of things to exterminate' but you see things like alien qear or even alien allies to crop up in the hands of the Imperium far too often to ignore them. The most desired equipment, miniaturized digital devices, is almost entirely alien-made for humans.

Tell me, can you recall any species really friendly to humanity? Every time Primarch talks/interacts with aliens, it seems to make matters worse. Fulgrim taking his sweet time with Laer instead of just bombing the planet into glass cost the life of 4 primarchs. Alpharius listening to xeno lies possibly doomed IoM to lose HH, as the aliens planned to kill both Chaos and IoM at the same time, instead of just sure way of killing Chaos, which resulted in Chaos being made stronger due to this idiocy. Horus indirectly fell due to aliens, same as Mortarion and a few others. Had they shoot first, HH would almost certainly be much weaker.

As for being terrified of arming Guard regiments with weaponry worth a damn...are you fucking kidding me? Allow me to present four scenarios.

Stock Guard unit versus Chaos/Tyranids/Basically everybody: God dammit, we need some weapons worth a shit!
Stock Guard unit versus traitor Guard unit: Fucking traitors, good thing we're as well-armed as they are!
Upgraded Guard unit versus Chaos/Tyranids/Basically everybody: AwRIGHT, these plasma guns are fucking awesome!
Upgraded Guard unit versus traitor upgraded Guard unit: Fucking traitors, good thing we're as well-armed as they are!

Yes, there's the risk of some of them turning traitor. Tough titties. Deal with lasgun-toting traitors by shooting lasguns at them, or deal with plasgun-toting traitors by shooting plasguns at them. You're no worse off, and the rest of your enemies most definitely are worse off.

Except IG is specifically not premier Imperium's fighting force. This role is carried by PDF. Equip traitors with plasma guns, and revolting regiment simply slaughters local planetary PDF forces without real opposition. For the Imperium, loss of whole planetary population is much larger problem than loss of occasional IG regiment. In addition, IG regiment with better weapons is much less scared by retribution of Astartes, Mechanicum or Sororitas when they rebel, a big no-no.

Finally, Imperium has much larger population than anyone else - so from their perspective, it's better to use it by fielding twice as large force with slightly worse weapons, than smaller but better armed one. It's twice as hard to subvert 2 regiments to Chaos than just one, twice as hard to wipe out 2 regiments with a single surprise nuclear bomb. It's modelling its army after Warsaw Pact, not NATO, and besides, even today NATO doesn't give every soldier Javelin launcher for the same reason Imperium doesn't hand everyone missile launcher or plasma gun.

Not really, if you're referring to the grand project for which the Emperor returned to Terra to work on. The project was a human webway, partly cordoned off and partly extended from the existing webway built by the Old Ones, and still used by the Eldar.

So yes, retiring from the front lines of the Great Crusade allowed Chaos to take root in some of the Primarchs.. and no, even had He completed the project, it would not have prevented the Heresy.

Why not? Next step was supposed to be dismantling of all warp engines and 'disappearing' navigators, plus much stricter regulation of psykers, IIRC, even if Heresy still happens whoever does it has no control over movement of his forces and is stranded (worst case) on Istvan, or has to fight tunnel warfare all the way to Terra (best case) bleeding forces the whole way.

That is the conclusion I came to a long time ago. It seemed to be even worse than betraying the Imperium and shacking up with Slaanesh etc. But what is worse than that? I couldn't come up with anything. The simplest theory was that it couldn't have been however, if it was the same thing but it had the added shock of being the first time, then that might fit the bill. (This would also fit the warning that Dorn ruminates on)

Conclusion I came to is that missing Primarch was A) pacifist (refusing to take part in Crusade, his Legion deemed subpar for extreme reluctance to fight), B) didn't joined humans, but, say, aliens (and was too alien for the Emperor when they found him), C) landed on planet too opposed to IoM (hyperdemocratical world or surviving dark age of technology planet, so was "disappeared" to appease factions too important for Imperium to function) or D) fallen to Chaos so early Emperor killed him for treason without telling other Primarchs what they just saw. These are the only things IMHO explaining both unheeded portents and potential handing of surplus Astartes to most professional Legion lacking insane quirks of the other ones.

But from what I heard, in earliest RT, there were really 20 Legions/Chapters, it's just creator of two missing ones left Games Workshop early so his ideas were quickly erased due to lack of rights to them? Or is it just urban legend?

[Imperial Overlord]

Things like Hrud, Orks, Tyranids, hell, even Eldar are nothing more but walking guns given flesh and intelligence.

Not at all true in teh case of the Eldar and the Hrud. Since multiple sources indicate that the Eldar have truly terrible weapons of mass destruction stocked away in case of a total war situation, a full scale extermination campaign against the Eldar would be disastrous.

Except IG is specifically not premier Imperium's fighting force. This role is carried by PDF.

Absolutely wrong. The best parts of the various PDFs are recruited by the IG. The IG

Equip traitors with plasma guns, and revolting regiment simply slaughters local planetary PDF forces without real opposition.

Where are these billions of plasma guns going to come from? The lasgun is cheap, rugged, reliable, and easy to produce. It can be recharged by throwing it's powerpacks in the fire. It will also kill most xenos dead. Plasma weapons can be produced only at rare, high end manufacturing facilities and guzzle down ammunition that comes from the other end of a long supply chain. Now remember that the IG must literally supply billions of troops across distances measured in light years using FTL that takes ships through hell. Most guardsmen will never be in the same sector as a traitor marine, let alone see one. On the other hand, platoon heavy weapon sections have autocannons, lascannons, and missile launchers that will kill a traitor legionnaire dead along with just about any other enemy and a good number of vehicles.

Why not? Next step was supposed to be dismantling of all warp engines and 'disappearing' navigators, plus much stricter regulation of psykers, IIRC, even if Heresy still happens whoever does it has no control over movement of his forces and is stranded (worst case) on Istvan, or has to fight tunnel warfare all the way to Terra (best case) bleeding forces the whole way.

Source? Because Thousand Sons is pretty clear that his plans involve making Magnus an uber-oracle and that doesn't sound like tighter psyker regulation.

But from what I heard, in earliest RT, there were really 20 Legions/Chapters, it's just creator of two missing ones left Games Workshop early so his ideas were quickly erased due to lack of rights to them? Or is it just urban legend?

The version I've heard is that GW left them blank so players could play around with the back story of custom chapters.

[White Haven]

Shit, man, the Guard already gut PDF formations the next best thing to effortlessly, barring a few outliers. Hamstringing Guard upgrade programs because you're afraid of making that process even easier is madness. Look, the strategy of the Imperium is one of delay and escalation. PDF can't handle an enemy? Tie them up until the Guard can arrive. Guard can't handle an enemy? Tie them up until more Guard arrive. Shitloads of Guard can't handle an enemy? Tie them up until the Astartes arrive. Astartes can't handle an enemy? FUUUUUUU*exterminatus*.

An upgraded Guard would have a much better chance of stopping that escalation before it hits the Astartes level, which lets the Astartes themselves be used in the role they're best at: going toe-to-toe against enemies in situations the Guard can't supply massive numerical superiority against. Rather than calling in companies of Space Marines to hold the line in an environment where an up-gunned Guard could handle things (areas where numerical superiority can do the job, when not attached to nigh-useless weapons), Astartes can be deployed to environments where it's impractical or impossible to do the job (Any environment either too confined to overwhelm high-end enemies of humanity with well-armed numbers, or too hostile for non-power-armour troops to effectively survive and fight).

Or, since the escalation strategy still works for the truly huge wars, for threats that shitloads of Guard just can't handle period. Threats against which you'll have more Astartes to deploy, because you haven't been pissing them away on shit that a properly-armed Guard should be able to handle in-house.

[Irbis]

Not at all true in teh case of the Eldar and the Hrud. Since multiple sources indicate that the Eldar have truly terrible weapons of mass destruction stocked away in case of a total war situation, a full scale extermination campaign against the Eldar would be disastrous.

Except, yes, Eldar were made in the same purpose as Orks - for war. They are more subtle weapon, but no less dangerous, as evidenced by the Eye of Terror. Yes, they are low priority targets due to being not that numerous or bloodthirsty, plus costly to fight, but they are exactly as friendly to humanity as Orks are, save for a few exceptions. They are just better at masking it.

Except IG is specifically not premier Imperium's fighting force. This role is carried by PDF.

Absolutely wrong. The best parts of the various PDFs are recruited by the IG. The IG

First, you seem to not finish sentence? Second, this is like saying US Army is worthless as Delta Force is only US fighting formation. PDF outweighs IG by several orders of magnitude, and unlike IG is present in every conflict on human world.

Equip traitors with plasma guns, and revolting regiment simply slaughters local planetary PDF forces without real opposition.

Where are these billions of plasma guns going to come from? The lasgun is cheap, rugged, reliable, and easy to produce.

Don't ask me, ask the guys who claim rearming IG would be free and painless. IG using most cost effective, reliable equipment is precisely my point.

Source? Because Thousand Sons is pretty clear that his plans involve making Magnus an uber-oracle and that doesn't sound like tighter psyker regulation.

Wasn't that the whole point of Webway Project? Make humanity much less reliant on psykers, precisely so you can tighten regulation and erase all the 'necessary evil' exceptions Emperor barely tolerated?

But from what I heard, in earliest RT, there were really 20 Legions/Chapters, it's just creator of two missing ones left Games Workshop early so his ideas were quickly erased due to lack of rights to them? Or is it just urban legend?

The version I've heard is that GW left them blank so players could play around with the back story of custom chapters.

Yes, but that supposedly happened after the guy left. I was just curious.

Shit, man, the Guard already gut PDF formations the next best thing to effortlessly, barring a few outliers. Hamstringing Guard upgrade programs because you're afraid of making that process even easier is madness.

No. Because the IG already is most cost effective formation they can field. Simple costs hamstring the process, plus the fact you need someone to keep IG in line. If you give IG anti-Astartes class weapons, surprise, they are much less likely to remain quiet.

Look, the strategy of the Imperium is one of delay and escalation. PDF can't handle an enemy? Tie them up until the Guard can arrive. Guard can't handle an enemy? Tie them up until more Guard arrive. Shitloads of Guard can't handle an enemy? Tie them up until the Astartes arrive. Astartes can't handle an enemy? FUUUUUUU*exterminatus*.

To delay them, you need numbers. If enemy first strike wipes out your force, there is no one left to delay. Same reasons why SM aren't all Terminator clad, Land Raider using force - resources.

An upgraded Guard would have a much better chance of stopping that escalation before it hits the Astartes level, which lets the Astartes themselves be used in the role they're best at: going toe-to-toe against enemies in situations the Guard can't supply massive numerical superiority against.

Except, upgraded IG are less numerous. IG cannot shield whole of IoM now, upgrade them and they suddenly can cover half the planets they did before. Regiment rebels? It uncovers twice as much front, and you need to throw a lot more at it to wipe it out. Soldier dies? He wasn't your average recruit with lasgun training, he was highly educated specialist, good luck trying to replace him by drawing from local population. Etc, etc.

Rather than calling in companies of Space Marines to hold the line in an environment where an up-gunned Guard could handle things (areas where numerical superiority can do the job, when not attached to nigh-useless weapons)

Except they no longer have numerical superiority. Good luck fighting Orks or small Tyranids, where your overkill weapons still kill one per shot, leading to this smaller, elite force being swamped and wiped out. Imperium already has heavily armed regiments of Stormtroopers, they aren't default type of regiment for a reason.

Or, since the escalation strategy still works for the truly huge wars, for threats that shitloads of Guard just can't handle period. Threats against which you'll have more Astartes to deploy, because you haven't been pissing them away on shit that a properly-armed Guard should be able to handle in-house.

Except, since your elite IG is smaller, it uncovers a lot of planets IG can no longer protect, causing Astartes needing to run from place to place trying to stamp out fires old IG prevented from ever arising, vastly increasing wear and tear on Astartes equipment, casing you to piss them away in pointless brushfire conflicts.

Case in point - occupying of rebelious planet. 10 IG regiments armed with lasguns do just fine, 4 armed with plasma guns can place nowhere near as much boots on the ground, insurrection and IEDs run rampart, eventually leading to open rebellion which calls in Astartes the larger force never needed. Most of the time, IoM needs more boots, not guns. If more proficient force is needed, it can be called upon, but the number filling role is one only IG can do.

[Imperial Overlord]

The Eldar were made to be weapons, but that doesn't mean that's an accurate description of a race with millions of years of civilization. Craftworld Eldar feel guilt over killing humans, the spend most of their lives removed from war which they view as something to be involved in only as necessity, and look on their exarchs as half mad murderers. They don't exist for war and in a better universe, most of them might never pick up a weapon. Humanity spread to the stars during the time of the Eldar's ascendance when they could have easily exterminated us. Describing them as living weapons or as a purely warrior race does them a disservice. They are, however, quick studies when it comes to learning the arts of war but they are Eldar and better than humans at just about everything they do.

As for the PDF, when you call something humanity's "premier fighting force" in English at least, you mean the best not the most numerous. The PDFs combined together are larger than the Guard, but the Guard is better trained and equipped and is the force that conducts offensive operations.

[Dominarch's Hope]

Its Orks who are the self perpetuating biological war machines. The Eldar are a little more complex due to the fact that they are more Warp-oriented and warp using whereas the Orks arent dependent on the warp for their combat power.

But the Eldar have actual free will. Orks? Dey iz Orky. Dats all dey iz.


Oh and actually, Astartes are first responder half the time. Shit like Armageddon isnt the norm. Really its, when everything can be used, Assasins, PDF, some Guard and Naval units and possibly inquisitorial forces, Astartes strike teams, then the Hammer of the Emperor.


In fact, tiny brushfire wars are exactly what current era Astartes and the SoB are best at. Stopping conflicts before hey leave a particular world. The Guard is for when the the scalpel just isnt going to cut it.

[Cykeisme]

Not sure about half the time, but one of the big specialities of Astartes is as a rapid-response strike force, so if there are any nearby they tend to deploy very quickly when a call for help goes out. They're described as sometimes showing up within days rather than weeks/months, and making planetfall within 20 minutes of arriving in orbit, etc.

[Imperial Overlord]

Not sure about half the time, but one of the big specialities of Astartes is as a rapid-response strike force, so if there are any nearby they tend to deploy very quickly when a call for help goes out. They're described as sometimes showing up within days rather than weeks/months, and making planetfall within 20 minutes of arriving in orbit, etc.

That's correct. The Space Marines are capable of prolonged, intensive conflicts but where they are truly without equal (in the IoM) is rapid response. That's one of the reasons they retain their own fleets. With the ability to fight for days upon end without resting and deploy by drop pod and teleporter from warships configured for orbital support the Astartes can strike at weakpoints and decapitate enemy command structures and then follow up aggressively. The IG with its countless soldiers, tanks, and artillery pieces does just fine with high intensity grinding warfare.

[The Yosemite Bear]

my understanding was PDF=National Guard/coast Gaurd suprised no one makes a warp incapable warship capable of dishing out major damage to the first spacehulk, ork rock, or Nid hiveship that shows up. (just guarding the coasts ya know)

[Cykeisme]

There are non-warp capable warships, but strangely enough I think they tend to be smaller than the real Imperial Navy bruisers. I think they're just referred to as "system monitors" and such.

The PDFs are more than the coast guard/national guard; by definition they are about ten times more numerous than the already insanely huge Imperial Guard, but obviously they are spread out.

[Simon_Jester]

There are non-warp capable warships, but strangely enough I think they tend to be smaller than the real Imperial Navy bruisers. I think they're just referred to as "system monitors" and such.

Blame it on the ratio of force to space. The Imperium's battleship and cruiser-sized warships are numerous, but not so numerous that they can afford to build one especially to protect a single normal star system. Assets that expensive have to be mobile, or restricted to the handful of fixed targets valuable enough to be worth that much protection.

[Imperial Overlord]

The Navy, for the most part, deals with warp capable vessels because of the vast areas they have to cover and the ability of warp capable vessels to concentrate their strength instead of being isolated forces that are easily picked off. Systems can build their own warships as part of the PDF those are usually system defence ships that are roughly as tough as a destroyer and really mean monitors which are heavy escorts with the firepower of a light cruiser. Add to that space stations, weapon platforms, and full fledged battle stations and the space around a heavily developed world can be hellishly well defended before you take the Navy or ground based defences into account.

[Black Admiral]

I especially like the Space Wolves not even disbanding their rune priests or restricting their actions because they use "the natural powers of Fenris not the unclean powers of the warp", a statement that combines both willful ignorance and towering hubris that dwarfs the Thousand Sons..

Well, setting aside the fact that from the Wolves' perspective the primary difference between a Rune Priest and a Thousand Sons sorcerer is control (as pointed out in Prospero Burns), they may not be entirely wrong about the source of their abilities; they're definitely capable of accomplishing much greater feats on Fenris than elsewhere (summoning massive storm systems for instance; ref. Battle of the Fang). Whether there's a causative link or not, of course, isn't clear.

(also, as far as "hubris" goes, I don't recall each Rune Priest having a Warp Pokemon that he uses for trivial tasks like cleaning his armour and weapons. Treating the Warp as a plaything is pretty much the definition of hubris)

[Imperial Overlord]

Well, setting aside the fact that from the Wolves' perspective the primary difference between a Rune Priest and a Thousand Sons sorcerer is control (as pointed out in Prospero Burns), they may not be entirely wrong about the source of their abilities; they're definitely capable of accomplishing much greater feats on Fenris than elsewhere (summoning massive storm systems for instance; ref. Battle of the Fang). Whether there's a causative link or not, of course, isn't clear.

That is true. It's also indicative that they're using sorcerous practices (location dependent rites). They just don't call it that, which is pretty much their M.O. for all things warpy.

(also, as far as "hubris" goes, I don't recall each Rune Priest having a Warp Pokemon that he uses for trivial tasks like cleaning his armour and weapons. Treating the Warp as a plaything is pretty much the definition of hubris)

That pales in comparison to denying that you're using the warp at all and that the Emperor's edict disbanding the Librariums doesn't apply to you at all. Ignorance, willful denial, and hubris in one package.

[Cykeisme]

Initially I was thinking, "Hey, if you don't have to make it Warp-capable, then you can make system monitors really huge and powerful on the cheap", but somehow I didn't consider the simple logic Simon brought up.. if you're going to spend that much resources and time constructing something, it had better be able to project its power into more than a single star system.

I guess the logic only applies to orbital defense stations, because then they don't even need to have engines, and don't need to worry about thrust-to-weight ratios. They can just pack craptons of guns and armour, with no mass ceiling, so they really are cheap (relative to the firepower they possess).


Random question, if I have a station in geosynchronous orbit around a planet, does that mean that any physical projectiles fired from that station already have sufficient velocity relative to the planet that they already "ignore" the planet's gravity well?
Not sure if that's phrased properly, what I mean is, its fired from a station that's already in a stable orbit, so anything released by the station already won't (immediately) fall back down to the planet.. therefore a shell fired does not "waste" energy that is "spent" as gravitational potential energy escaping the planet's gravity, right?

Probably something that 40k doesn't go "hard" enough to care about, but just for my internal "head-canon"

[Cykeisme]

Not really, if you're referring to the grand project for which the Emperor returned to Terra to work on. The project was a human webway, partly cordoned off and partly extended from the existing webway built by the Old Ones, and still used by the Eldar.

So yes, retiring from the front lines of the Great Crusade allowed Chaos to take root in some of the Primarchs.. and no, even had He completed the project, it would not have prevented the Heresy.

Why not? Next step was supposed to be dismantling of all warp engines and 'disappearing' navigators, plus much stricter regulation of psykers, IIRC, even if Heresy still happens whoever does it has no control over movement of his forces and is stranded (worst case) on Istvan, or has to fight tunnel warfare all the way to Terra (best case) bleeding forces the whole way.

That's actually a very interesting scenario you raise. It would certainly have made the Heresy itself very different, with, as you say, crazy tunnel fighting and stuff.
Actually, I'm not very clear as to what the inside of the webway looks like. I've only seen vague descriptions about how there are some passages that permit entire fleets (or even craftworlds to traverse), while others are footpaths where people literally walk through it, on foot. Then there's Commoragh, an entire star system (?) within the webway. Is there a source that describes what exactly it's like in there?

Note: I don't think the Human Webway would have stopped the Primarchs from falling to Chaos, because the chain of events that begins with Erebus, Lorgar and Horus were not reliant on the deleterious increased exposure to the Warp due to Warp travel.
Also, as it turned out, the Human Webway was still a very long way off from completion, so this alternate scenario is that it was completed earlier, before Primarchs started to get corrupted.
Besides, the entire project was something that was intended for use after the Great Crusade is effectively concluded, because they'd still need FTL ships to locate and bring new worlds into compliance. The Human Webway would then be extended to worlds that are already added to the Imperium.

[Dr. Trainwreck]

A human webway depends on how much of an autocrat the Emperor wants to be. If the Emperor can simply cut off all webway gates around Horus the moment he turns on him, the entire thing goes much better.

Also a complete webway means that Magnus either never turns traitor, or under much different circumstances; the reason Magnus was targeted for arrest in the first place was because, in addition to violating the sorcery ban, he inadvertedly fucked up what little of the webway was already under construction. With a complete webway, Magnus could either not cause any damage with his psykermail or just not rely on sorcery.

Granted, Tzeentch was already on his ass so that meant he would fall later on, probably in some civil war dwarfing even the Heresy.

[Imperial Overlord]

Granted, Tzeentch was already on his ass so that meant he would fall later on, probably in some civil war dwarfing even the Heresy.

Unlikely. Magnus was a believer in the Emperor's vision and had a better understanding of it than most Primarchs. That's why Tzeentch didn't try to get him to fall and instead engineered an unhealable breach between the Thousand Sons and the rest of the Imperium. Just a little more restraint or a little less fear on the part of Russ, who was being lead around the nose by Tzeentch and egged on by Horus and Valdore, and the Thousand Sons would have accepted their punishment. Tzeentch had to fan the fires of fear and hatred for decades among the Space Wolves and fuel complacency and hubris among the Thousand Sons and to engineer the fall of the Thousand Sons and it still only just succeeded.

[Vaporous]

Here's a question. Let's say that, by the power of handwavium, Horus' alterations to Russ' orders doesn't go through. What would have happened to Magnus if Russ had taken him back to Terra alive? Does the Emperor do to him and the Thousand Sons whatever he did to the lost Primarchs and their legions*? Does he strap Magnus to the Golden Throne and use him to keep the gate shut while the Emperor runs the war on Horus himself?


* Spoiler

In Aurelian, it is implied that one of Lorgar's possible fates involved him being ritually sacrificed as part of a warp-curse by the Emperor to destroythe WordBearers. This might have been what happened instead of Monarchia, or if Lorgar had tried to resist there. Since I'm pretty sure this information comes from Kairos Fateweaver, it should be taken with a healthy dose of salt.

[Imperial Overlord]

It's hard to know what the Emperor intends. We know he's not good at playing father to his godlike sons and we know he's capable of being extremely harsh and ruthless. Magnus has broken the Nikkean Edict and caused severe damage, but he is one of the few people who actually has the ability to help in undoing it. The timing also matters.

Horus has fallen. That was what Magnus was trying to warn the Emperor about after all and by the time he gets taken back to Terra there might be more evidence of the Heresy. Even if there isn't, if the Emperor does not immediate destroy Magnus and the Thousand Sons (to decide their fate, to punish but not destroy, investigate Magnus's charges) then when the Heresy breaks out it could go very differently.

1) The Space Wolves will be near/at Terra and not have taken loses fighting the Thousand Sons.

2) Neither will the Custodes or the Sisters of Silence.

3) The potential addition of the Thousand Sons to the loyalist ranks with their fleets and warp craft expertise.

Things could go very badly for Horus.

[Black Admiral]

Except for the rather silly retcon now extant that Magnus sent his warning to the Emperor after the Dropsite Massacre - which makes him look stupid, actively in collusion with the Traitor Legions, or both.

[J Ryan]

Except for the rather silly retcon now extant that Magnus sent his warning to the Emperor after the Dropsite Massacre - which makes him look stupid, actively in collusion with the Traitor Legions, or both.

Probably best to ignore that retcon. That would mean that Russ was sent pick up Magnus after Horus went to the other side, but still decided to follow his orders about what to do with Magnus.

[Vaporous]

I'm not sure that's a retcon so much as McNeil screwing up the timeline by mistake.

[Cykeisme]

Regarding Magnus sending his warning post-Istvaan Dropsite Massacre, if you guys are referring to The Outcast Dead, I think it's unofficial consensus that it's a gaffe on McNeil's part.
Which is a shame though, the book did give a glimpse of a few other interesting things that don't appear anywhere else. Not to mention a surprise, as you think Graham McNeil of all people would know the chronology of major Heresy events like the back of his hand.

Also a complete webway means that Magnus either never turns traitor, or under much different circumstances; the reason Magnus was targeted for arrest in the first place was because, in addition to violating the sorcery ban, he inadvertedly fucked up what little of the webway was already under construction. With a complete webway, Magnus could either not cause any damage with his psykermail or just not rely on sorcery.

Eh, good point. If the webway was complete, Magnus would not have needed to use sorcery to send his urgent warning. He could simply have used the webway to stroll over to Terra and warn the Emperor in person.
A whole slew of other inter-dependent events change, of course, but that's just one thing that wouldn't have happened.

[Kojiro]

Regarding Magnus sending his warning post-Istvaan Dropsite Massacre, if you guys are referring to The Outcast Dead, I think it's unofficial consensus that it's a gaffe on McNeil's part.
Which is a shame though, the book did give a glimpse of a few other interesting things that don't appear anywhere else. Not to mention a surprise, as you think Graham McNeil of all people would know the chronology of major Heresy events like the back of his hand.

Given GWs rules writing and constant revision I'd be stunned if they they have any official timeline. Like the missing primarchs I'm certain they really don't have an explanation and for what it's worth, I hope they never do. GW should focus more on advancing their storyline than meddling with it's past.