At the first floor desk, Rose found Jill Shanosky, the guard, waiting behind the front desk.
"I came on duty at seven," she told Rose after her brief questioning. "Made my round when I arrived and again at eight-thirty and ten. Mr. Denny, the accountant, was working in his back office. Jack and Helen arrived at eight. When I heard the scream from upstairs, I pushed the button that locks the outside doors both ways, hit the silent police alarm, and ran up. Helen was already there and pointed out the blood spot. It was the cops who found Jack in the tank."
"What were you doing when not on rounds?" Rose asked, observing the splint on the guard's left thumb.
"I was here at the desk, doing logic puzzles. It's my hobby."
"I don't mean to seem callous," Denny said tartly, "but I have to keep working tonight. Our fiscal year ended a couple of weeks ago, on June 30, and our auditors need preliminary numbers tomorrow. I'm sorry Jack is dead. As I told the officer, I know nothing about it."