Ah, an excellent and succinct explanation, "It happened because it did"; something of a standing loop in time, powered by the DEs killed in August of 1981. I enjoyed the explanations and the ending brought a smile.
One small homonym problem, though:
"... real break on Dark activities ..." should be "... real brake on Dark activities ..." if I'm understanding your meaning correctly.
Congrats on another thoroughly engrossing story.