Worst Necessary plot detail

[Setzer]

In your opinion, which detail in a story was the most ridiculous.
Keep in mind that the plot point must have occured for the stroy to continue as it did.

My vote goes to this story called "In the Keep of Time."

It was in a post apocalyptic setting, where a man named Jason created a colony of people who survived a nuclear war (more on this later) they eventually mutated to survive. Jason's son David had been kidnapped, and locked in a cryogenic storage chamber, along with several other abducted children, by this loony old lady who wanted to start a master race after the Apocalypse.

Jason had written a sort of constitution/ message for David, yet some how Jason and David became corrupted to Jahben and Dahben by the mutants.
However, the rest of the language stayed the same, from spelling to grammar to pronunciation.
Jason believed his son was alive, and had the mutants look out for him.
David got later exaggerated to a messianic figure, with his return being something on the level of the second coming.
However, because of this fuckup by the mutants, when David came around, and they asked if he was Dahben, he didn't know what they were talking about!

Now for why the nuclear war happened. The Human race had built computers to rule over them. This would undoubtedly include control of nuclear weapons. However, not only did the computers decide that a nuclear war would be the only way to eradicate "nationalistic rivalries", they actually suppressed all who tried to resolve international tensions peacefully.

Imagine if they were in charge of the world during the Cuban missile crisis!

[General Zod]

how about half the plot devices in Enterprise?

[Warspite]

The Matrix's humans as an energy source.

[Queeb Salaron]

The iceicle and the supernatural posession/kiddie porn scene in "Lovely Bones."

[The Aliens]

Voyager using the Borg to death- I wanted to kick the screen and cry in Dark Fronteir.