The night shift is quiet except for the machines breathing down the hall. The gray cat, Marrow, walks ahead of me like he owns the place. By March I figured out the rule nobody says out loud: wherever Marrow curls up to sleep, that bed is empty by dawn. Tonight he stops outside Room 14. Then he turns and looks straight at me with flat yellow eyes.

I check my chart. Room 14 is Mr. Avery, and he's stable tonight. No reason for the cat to pick him. I crouch down and try to shoo Marrow away from the door. He doesn't move. He just keeps staring at me, waiting to see what I'll do.

I call Diane, the senior nurse who trained me. She picks up on the first ring even though it's 3 a.m. "Which room?" she asks. When I say 14, there's a long silence. "Don't let the cat in," she says. "Whatever you do tonight, keep that door shut."

I keep the door shut like she said. But around 4 a.m. I hear Mr. Avery calling for help, weak and scared. The cat is still outside. If I open the door to help him, I break Diane's only rule. If I don't, I'm leaving a dying man alone.

I keep the door shut and cover my ears. The calling stops after a while. At dawn I open the door. Mr. Avery is fine, sleeping peacefully, color back in his face. But the cat is gone, and so is Diane. They find her car still in the lot and her shoes by the exit. The rule got paid. Just not by who I expected.