PERKINS LET ME USE HIS FAX MACHINE to send copies of Mary Wagner’s time sheets over to the Bureau for cross-referencing. Then he set me up with a maintenance uniform and a name tag that said “Bill.”

Bill stationed himself in the basement, within sight of the stocking area where housekeeping loaded up on paper products and cleaning materials. Just after 7:30, the new shift filtered in.

All of them were women, all in the same pink uniform. Mary was the tallest in the group. Big-boned, that’s what some people would call her. And she was white, one of the few on the housekeeping staff.

She certainly looked strong enough for the physical work Mary Smith had done—manipulating Marti Lowenstein-Bell’s body in the swimming pool, moving Brian Conver from the hotel room floor to the bed.

Bill stood maybe twenty yards away from her, facing a fuse panel, his face partially hidden behind its door.

Wagner went about her work quietly and efficiently while the others chatted around her, most of them talking in Spanish. She stuck mostly to herself, just as Perkins had described. Hers was the first cart onto the freight elevator.

I didn’t follow her upstairs. The hotel corridors would offer no cover, and my priority was to interview her at home later, as myself. That meant a limited surveillance for Bill at the hotel.

My best opportunity came during the lunch hour, when the staff cafeteria was filled to capacity. Mary sat by herself at a table near the door, eating a tuna salad sandwich, writing in a clothbound book, presumably a journal of some kind. I wanted to see that journal. Her conversations with the people around her seemed to be little more than polite hellos and good-byes. The perfect employee.

I decided to pull myself out at that point, and went back to Perkins’s office in the basement. I gave him a courtesy debriefing. As we were talking, my beeper went off.

“Excuse me.” I got Karl Page in the crisis center.

“I thought you’d want to know right away—yeah, just a second, I’ll be there—her time sheets check out perfectly. Mary Wagner wasn’t at work for at least two hours before and two hours after every estimated time of death. No exceptions. Cha-ching!”

“Okay, thanks. I’m out of here. She’s working today.”

“When did you last see her?”

“About ten minutes ago. I have to go, Page.” Perkins was looking at me expectantly, and I didn’t want him asking too many questions. The receiver was halfway back to the cradle when I heard Page shout, “Wait!”

I gave Perkins a sorry with my eyebrows. Sometimes Agent Page could be a little exasperating, almost as if he was trying too hard.

“What, Karl?”

“Mary Smith’s last e-mail, Alex. The murder that’s supposed to happen by twelve tomorrow.”