oy brought a friend home to play.

A bright, articulate boy, he and Roy appear to be a good match. They like to throw things and catch them. They are both strongly in favor of rolling down hills, whenever the opportunity might present itself. And they prefer running to walking if given a choice.

During the course of their time together, an unexpected visit from a neighborhood friend changed the rollicking dynamic. It was almost instantly apparent that Roy’s two friends were either of a mind to mate with or to murder one another. Their chemistry was toxic. Two children who’d never set eyes on each other ten minutes prior were throwing beans at each other, trying to drop things down the other’s shirt, verbally challenging one another and, occasionally, stealing small things of no import so that the other might impotently try to recover the item from their gleefully clenched fist.

Besides being unprecedented in my experience as mother to The Three, the interaction between the pair of them was weird and kind of horrible. I was reminded of a preschool problem we encountered when Roy was four. There was a period of a few weeks on the playground at this sweet, small church-based program in which a classmate, driven to a state of Berserker fury by whatever turn his play with Roy had taken, would put his small hands around Roy’s neck in a deliberate—if entirely ineffectual—show of his wish to obliterate Roy’s maddening presence.

At the time, one of the teachers said she wondered if there wasn’t some sort of chemical component to the boys’ antagonism. Some people, she said with the quiet wisdom of years spent as a student of human behavior writ small, just don’t like each other.

Roy’s preschool problem was solved easily enough. He finished the last few weeks in the class, but we pulled him out for the summer. And unbeknownst to me, Scott told him that he was welcome to kick his classmate in the groin if he were to so much as wave his hands in the general direction of Roy’s throat. Roy got his kick in, you can be sure; as sure as I am that he goaded that poor, high-strung child into trying to choke him just one more time so that he could.

I’m not sure what unseen forces were at play between Roy’s friends last week, if they were simply fierce, instinctive rivals for the attention of my son or there was some dark human chemistry at work. What is certain is that nothing is easy anymore. Their play is colored differently, the light filtering through gender and age, shading things darker here, lighter there. The currents moving beneath their words and actions seem more dangerous. The insults are sharper, the blows harder and the implications of all of it heavier than I’d imagined it might be when Roy still had a summer to play before kindergarten began.