It was fatal.

It was the gap through which their entire conspiracy was destroyed.

They could plan a murder in front of Elena because they could not conceive of Elena as a witness, and so they made her the one witness they never guarded against, and she brought them all down.

There is a justice in that so precise it feels almost designed.

The people who win by treating others as invisible are undone, again and again, by the invisibility they impose, because a person you refuse to see is a person you cannot account for, and the unaccounted-for is where every arrogant scheme goes to die.