Young, confident, beautiful Petra had come to Chicago fresh out of college to work as an intern on Brian Krumas’s Senate campaign. For another moment, my brain stayed frozen. Then I remembered my video monitor. I have one because the front door is remote from my office and invisible from the hallway. My fingers trembled as I tried to boot up my computer. The modem had been yanked free from the port. The middle-aged cop stood over me while I found the wires and got my system hooked back together. I pushed the ON button. The Apple gave its opening chord, and I breathed a little prayer to the God I don’t believe in. Saint Michael, patron of police and private eyes, get me my video files.

While the cops watched, I pulled up the images. My lease-mate had come in at 11:13 and left at 4:07.

Four-seventeen, while I was walking away from Johnny Merton, three people showed up, hats pulled low over their heads, coat collars hiked well up, faces and sexes both unrecognizable. They were all roughly the same height; in their bulky coats, it was hard to tell if they were all the same girth. I thought the one on the left was the stockiest, the one in the middle the thinnest, but I couldn’t be sure. We could hear the buzzing as they rang the front door, and then one of them tapped in the door code.

“Who else knows that code?” the male cop demanded. “Who besides the people you mentioned?”

“I-my cousin knew it.” I could hardly get the words out. “I let her use my machine one night when she lost her Internet access.”

“Is she in this picture?” the woman asked.

I froze the image on the screen. A professional might be able to decode race or sex from these grainy pictures, but I couldn’t make them out. I shrugged helplessly.

I called Petra’s cellphone but only got her voice mail. I tried the Krumas campaign, but they’d shut down for the night.

The cops sprang into action, calling codes in-44, 273, 60-possible kidnapping, possible assault, possible aggravated burglary. The possibilities were endless and chilling. Squad and tac cars began pouring in while I made the hardest of all the phone calls: the one to my uncle Peter and his wife, Rachel, to tell them their oldest child had disappeared.