Detective Trimble is investigating strange suicides, even of prominent citizens. Why is it happening? Trimble suspects the new opening of universes, finding universes of what-might-have-beens where your life turned out differently is the cause. And then psychologically it hits him as it must have hit everyone else:
"There was no luck anywhere. Every decision was made both ways. For every wise choice you bled your heart out over, you had made all the other choices too. And so it went, all through history...."If every choice was cancelled elsewhere, why make a decision at all?"
The ending is left ambiguous leaving many possibilities on the table. Or, more likely, all were taken.