water gun, Mrs. Ebbermann?" I asked casually.

"Oh, she wanted to bring her water gun with her, poor baby. But I made
her leave it at home--I was afraid she might squirt people with it.
But I shouldn't have done that! She's a good girl! She wouldn't squirt
anybody!"

"Sure not, Mrs. Ebbermann. Does Shirley have a key to your apartment?"

"Yes. I gave her her own key, a pretty one, with her initials on it,
for her seventh birthday, so she wouldn't have to push the buzzer when
she came home from school."

"Where's your husband?" I asked taking a look at Ramirez' notebook to
get her address.

"Shirley's father? Somewhere in Boston. We've been separated for two
years. But I wish he were here!"

"Would you give me the key to your apartment, Mrs. Ebbermann? We'd
like to take a look around."

She gave me a key. "But she's not there. I told you, that's the first
place I looked."

"I know," I said. "We just want to look around. We won't disturb
anything."

Then His Grace and I got out of there as fast as we could.

* * * * *

I keyed open the front door of the apartment building, and we went
inside. Neither of us said anything. There was no need to. We knew
what must have happened, we could see it unfolding as plainly as if
we'd watched it happen.

Nestor had seen Shirley sneak off from her mother and had followed
her. In order to get into the building, he must have come right in
with her, right behind her when she unlocked the outer door. Then
what?

The chances were a billion to one against his ever having been in the
building before, so it stood to reason that all he would have been
doing is watching for an opportunity and--the right place.

The foyer itself? No. Too much chance of being seen. The basement?
Unlikely. He must have followed her into the elevator, and she would
have pushed the button for the seventh floor, where her apartment was,
so there wouldn't be much likelihood of his getting a chance to see
the basement. Besides, there was a chance that he might run into the
janitor.

* * * * *

The Duke and I went into the old-fashioned self-service elevator, and
I pushed number seven. The doors slid shut, and the car started up.
The roof? No. Too much danger of being seen from other buildings
higher than this one.

Where, then? I looked at the control panel of the elevator. The button
for the basement was controlled by a key; only the