Because the same instinct that makes me good at my job took Colm’s small, innocent observation and treated it as an anomaly to be traced to its root cause, and my mind, left alone with it, did not consider the ten gentle explanations before the ugly one.

It went straight to the ugly one and started building the case.

That is the thing I understand now that I did not understand then: that a mind trained to assume the worst-case failure will find it everywhere, even where it does not exist, and will assemble ordinary, innocent facts into a proof of exactly the disaster it fears most.

I loved my wife.

I had no reason on earth to believe she would betray me.

And within sixty seconds of my son’s question, I had already convicted her, because a locked room in my own head had been waiting my whole life for evidence that the good thing I had was too good to be true, and Colm had just handed it a key.