We have indoor cats for a reason: we want to keep them safe. They’re less likely to get hit by a car, get fleas, get into fights, or get sick—in fact, I’m thinking about following the same policy with our son Sean.

One of our cats, however, has ideas of his own. Puck, who is named after a particularly mischievous character from A Midsummer Night’s Dream, is a tomcat stuck in a house cat’s body. He rushes the door every time we go in or out, and he manages to get out enough to embolden him to try again—and again, and again. Earlier this summer, he figured out how to pull open the sliding screen door our landlord just installed. One day we looked out on the back deck and both cats were out there nosing around the landscaping.

Tuesday morning, at about four o’clock, he was motivated to find a different way to get outside: there was another neighborhood cat on Puck’s deck. We heard them yowling at each other through the open window, and then we heard a crash. Danielle had to give me a nudge to go downstairs and investigate. When I saw the screen lying on the floor, I thought I’d better put on some pants and go find the cat.

Once clothed, I switched on the back light and saw Puck sitting out there, surrounded by tufts of his enemy’s fur. And Puck didn’t have a scratch on him.

He’s done this once before, down in Norfolk. Danielle was deployed, and the unmistakable sounds of a cat fight woke me up. That time, Puck had not stayed near home, savoring his victory. I had to wander around the neighborhood for a while before spotting him crossing the street. Back at home, our well-behaved cat, Oberon, didn’t seem to recognize Puck. He must have picked up a funny smell while carousing around the neighborhood. Oberon acted like a disapproving older sibling for weeks.

Looking at Puck now, curled up in the chair next to mine, you’d never guess there was such a fierce warrior lurking within.