"What do you want to know about the building?"

"I was wondering if Jim Scoby, the night watchman, was permitted to
carry a key to the Cameron suite. Jimmie does not know whether he was
or not, and I thought you might have heard Fremont talking about
matters there."

"I presume Fremont can tell you all about that. Suppose Scoby did have
a key? What of it? Fremont says Mr. Cameron locked himself in that
night, or was to do so, and that shows that the man who did the job did
not need a key. He must have been admitted by Mr. Cameron."

"There were strange doings in that suite that night," Nestor said,
almost as if talking to himself. "I can't quite get the hang of it,"
he added, taking a flat steel key from his pocket, and holding it up
for the inspection of the other.

Shaw took the key and held it up in the moonlight, examining every
detail of it.

"That is a key to the suite," he said. "Fremont has one like it.
Where did you get it? It looks new."

"It is new," Nestor went on. "It looks as if it had been made to order
recently. Now, whoever made it did not get it exactly right at first,
and was obliged to file it down. I have known night watchmen to make
keys."

"An old trick," admitted Frank. "Well, let us take it for granted that
Scoby was not permitted to carry a key and that he had one made, for
some purpose of his own. What does that lead up to?"

"I found this key in front of the safe," Nestor continued, after a
moment's deliberation. "It was undoubtedly dropped there by one of the
men who visited the rooms that night. I have been wondering if it was
the watchman."

"You have some other reason for supposing it was Scoby," Frank said.
"Go one and tell me about it."

"Yes, there is another reason." Nestor continued, smiling at the quick
way Frank had taken him up. "I found this Grand Army button and this
cloth raveling in front of the safe, too, not far from where the key
was discovered."

"Well, did the watchman wear a Grand Army coat that night?" asked
Frank. "Lots of unworthy people wear Grand Army coats."

"He did," was the reply. "He wore a blue coat with Grand Army buttons,
and one of the buttons was missing from the right sleeve when I saw him
in the corridor as I passed out. He probably caught his sleeve on
something in the safe and ripped the button off. He either did not
notice the loss of the button or had no time to pick it up."

"You're locating him in a compromising