It was one of those warm late-winter nights that show up without warning in southeastern Michigan. Moist air stirred over huge piles of snow, giving rise to fog banks that drifted among the trees, cars, and houses. I had just come in from a walk through this almost magical weather when my phone rang. As any veterinarian knows, getting a call this late at night could mean only one thing: a sick animal.

"Dr. Petty? This is Mrs. Byrd. I think there's something wrong with my little dog. He won't eat and it's been going on for a couple of days. I'm getting really worried."

A call that at first had seemed like an obstacle to a good night's sleep was becoming a roadblock. But I took down Mrs. Byrd's address. I recognized that it was in a once-wealthy Detroit neighborhood—broad tree-lined avenues had been flanked by substantial homes and mansions. Instead of alleyways, canals had been built for the rich inhabitants to park their boats for easy access to Lake Ste. Claire.

Now, however, the neighborhood was full of drug addicts—and worse. Most of the buildings that hadn't been burned to the ground were crack houses. The canals were filled with stagnant water, which at this time of year was frozen into dirty, greasy ice. With a sigh, I got into my car and headed out.

As I looked for the address I thought I must have written down the wrong directions. Surely no 90-year-old woman could survive in a place like this. There didn't seem to be a single habitable house. Blackened foundations jutted up through the snow. The fog banks that had appeared so magical in my cozy neighborhood here seemed like hiding places where evil lurked.

I was about to give up when I came upon what looked like the lit-up parking lot of an all-night convenience store. I realized that this was the address. The house was bathed in the blue light of mercury vapor lamps, and a high chainlink fence surrounded the property. In the middle of it all stood Mrs. Byrd, wearing a leopard fur coat over her nightclothes and a red wig put on sideways, tufts of gray hair peeking out.

"Yoo-hoo, Dr. Petty, here I am," she called, as though she were standing in a crowd of other elderly ladies wearing leopard fur coats. I grabbed my doctor's bag and got out of my car wondering if it would still be there when I returned. I crunched up the snowy path to her large but neglected home and stepped inside.

An unnecessary procedure: Dr. Michael Petty went through the motions of examining a dead patient when its owner wouldn't give up hope without his final verdict.

Examining the little dog wasn't necessary. The fetid odor coming from the parlor told the whole story. Cookie hadn't been eating because Cookie was dead. I looked at Mrs. Byrd and opened my mouth to tell her, but then I saw the pitiful look on her face. I knew I couldn't say anything without first examining her little companion.