“Or maybe you ran out the door. Maybe you fled. I’ll buy you a bag of treats. The same thing, salmon Greenies, because I know that’s what your mother bought for you, lots and lots of bags of them in a cupboard. And grain-free turkey and salmon, which I also saw in the kitchen, plenty of it. She made sure you were well fed, had lots of healthy things to eat, didn’t she? You don’t seem to have fleas, but I’ll give you a bath and get you cleaned up, so you’re probably going to be angry with me.”

It’s almost midnight as I pull into the Shaw’s supermarket parking lot, illuminated with tall light standards and bordered by bare trees moving in a wind that has died down considerably.

“I guess I could call you Shaw, since this is our first outing together.” I park near the brick columned entrance. “I apologize I don’t know who you are exactly, and I don’t want you to worry, but I’m going to have to leave you in the car for a few minutes because I don’t have anything at home for a cat. Only things for a dog, his very boring fish diet and sweet-potato treats. An old greyhound named Sock who is very shy and probably will be afraid of you.”

I leave her wrapped in the towel in the driver’s seat, shut the door, and am pointing the remote to lock it when headlights blind me as another car turns in. For an instant I can’t see, and then a window rolls down and Sil Machado is grinning at me.

“Hey, what’s doing, Doc?”

“Cat shopping.” I walk over to his Crown Vic. “You following me?”

“We sure it’s really her cat?” He shifts the car into park and props an arm on the door frame. “And yeah. I’m following you. Somebody’s got to.”

“Logic would tell you it’s her cat. But I don’t know it for a fact. She certainly seems lost and homeless.” I look around at the almost empty lot, at someone rolling a shopping cart at the far end of it. “Are you coming inside?”

“Don’t need anything at the store,” he replies. “Just making sure you get home okay.”

It seems a strange thing for him to say.

“I know you’re used to riding around all over the place at all hours. But I’m just making sure,” he repeats.

“Do you know something I don’t?” I notice bags of evidence in the dark backseat, including those I collected.

“Someone who’s familiar with Cambridge, right?”

“Someone who’s familiar with her house, her neighborhood. Someone who made himself familiar, anyway.” I step back to look through the driver’s window of my SUV, making sure the cat’s okay.

She’s sitting up on the towel.