As soon as Farley’s collar was unhooked, he took the nearest, steepest slope down into the dell. By the time he reached the bottom, he was fishtailing a little, his looser back legs having descended slightly faster than his front ones. He fetched up between a black Lab mix named Scout and Scout’s owner. To get between a rival dog and its owner was strategy. Cut off the opposing army from its supply.

“Seen anything good?” Scout’s owner asked.

Jacob was in the habit of bringing his camera to the park, and it was around his neck. “A wasp’s nest, but it’s too high. Did you start that job at the hospital?”

“Yeah, you know, I don’t think I like working with people. Too much politics.”

“Because you’re working on insurance?” The job had something to do with syncing the hospital’s IT back end with an insurance company’s.

“I don’t mean politics politics. Hey, I’m just the tech guy.” He spoke with a dad-like cadence. “I mean, just, people.” He laughed at himself. Scout barked sharply, and with a curved plastic launcher, the man slingshotted a tennis ball. “Farley’s looking good. I know for a while you had that … ” He crooked an elbow to mime the sling with which Jacob sometimes had to support Farley’s back legs.

“He likes the cold.”

“Most of them do.”

Farley trotted away toward a tree—a black walnut—on the far side of the dell, where the ground underneath was dark and raw. Maybe that was something black walnuts did to the ground deliberately. The mud of the park was a famous delicacy, so Jacob followed, clapping his thigh to call Farley to heel.