Z’s cough turns out to be just that — a cough — but while daylight, a trip to the pediatrician, and the purchase of a cool-mist humidifier have brought calm to our roiling first-time-parent worries, the strange noise that started it all continues to echo in my mental hearing: in the amber nightlit nursery, as my hands moved as deftly as a surgeon’s, tucking Z into a new diaper like a pickpocket in reverse, he emitted a rising squawk that registered as a more primal distress — not just discomfort but existential dread.

Of course I’m reading too much into it. (That seems to be what first-time parenting is all about.) Z’s weird noise, I see now, reactivated some part of my brain that’s been dormant for decades, a nerve cable buried deep in my cerebellum stretching back to my own childhood, when I lay awake many nights gripped in fears that were the residue of too much scary TV, too many horror movies, and one too many skims through the best — which is to say, the most extreme and upsetting — parts of William Peter Blatty’s The Exorcist.

These materials were my prepubescent pornography, an irresistible lure of the forbidden and transgressive that was fun enough to consume by day, but with sundown turned toxic, a kind of slow acid bath for my imagination. Probably because I was raised as a Catholic, it was the devil stories that got to me the worst: The Omen, The Devil’s Rain, Beyond the Door. I envisioned myself being possessed by a demon, and would play out in my head dialogues between God and Satan about whether my nine-year-old soul was worth the trouble of fighting over.

These fears may be in Z’s future, though I expect my wife and I will be more careful about leaving copies of The Exorcist lying around. (The youngest of five, I inherited all manner of cultural detritus, including the Batman comics with which I learned to read.) For now, I’m relieved to know the tickle is in his throat, and not in his mind.