Once, when I was seven, I was chased by a dog.

We lived in a trailer park then, my brother, our mother, and me. There were lots of dogs around, most of them running loose. I didn’t mind. I like dogs. But dogs . . . dogs don’t much like me in return. Puppies do. Puppies like everyone. They’d crawl in my lap, chew happily on a finger or the tattered edge of my sneaker. Dogs are different—one sniff of me was enough. The upper lip would peel back, ears would flatten, and the warm brown eyes would go glassy and slide sideways as they hunched away with tail tucked beneath their legs. Dogs don’t just not like me; they’re afraid of me.

Except for Hammer. Hammer wasn’t right; not right being flat-out crazy. One hundred pounds of shepherd mixed with Rottweiler mixed with God knew what else, Hammer wasn’t afraid to look at me as the other dogs were. No, Hammer liked to look at me. He liked to think about me. If anyone thought animals didn’t think, didn’t plot, didn’t plan, then they’d never met Hammer. Two trailers down and one of the few dogs in the park kept on a chain, he watched me every day as my brother and I walked to school. He never barked. He never growled. He never even moved. He just watched.

Because of his lack of apparent aggression, any other kid might have been tempted to pet him. Not me. Even at seven, I knew a monster when I saw one. It didn’t matter whether his owner had made him into one or he’d been born one like me. Hammer was Hammer. You didn’t pet him any more than you petted a rabid grizzly bear. You just walked by and kept your eyes on the ground. You never looked. . . . Just as Hammer never moved.

Until he did.

Hammer was bad inside, wrong, and as I recognized him, he recognized me. And when drunk old Mr. McGee let the chain finally rust through, Hammer came for me. I had my dollar-store sneakers and a bagged lunch my brother had made for me, but I didn’t have my brother. He’d gone ahead, although he was still in sight. He never failed to make sure I was in sight. I’d forgotten my backpack like kids do. I’d catch up. No big deal, until Hammer made it one.