was
found in the heart of Africa, in the kinky hair of a native. There's blood
on it, too, for men have been killed trying to steal it, and trying to
prevent its being stolen. It's the most valuable necklace in the world."

The boy mounted the staircase as he spoke, leading the others to his room,
which was at the front of the house on the second floor, directly over the
apartment used by his father as a library, or study. The suite occupied by
the boy was elegantly furnished, the only thing which marred the tasty
arrangement of the place being a steel safe which stood between the two
front windows of the sitting room.

"There," said Frank, closing the door of the room behind the little party,
"they got the necklace out of that safe."

"How did they open it?" asked the lieutenant, and Jimmie laughed.

"Frank never closed a door in his life," the boy said.

"Was the safe open?" asked Lieutenant Gordon.

"Yes," was the reply, "it was open. I had just been there to get some
money when I heard a scrap going on in the corridor and rushed out,
leaving the door open, like a sucker. The necklace was taken while I was
gone."

"Anything else taken?" asked Ned.

"Not a thing. Oh, I guess the thief got a couple of dollars there was in
the cash drawer, but nothing else was disturbed."

"How long was he in the room?" asked the lieutenant.

"Oh, perhaps fifteen minutes. What I mean is that it must have been about
that length of time before I came back here. You see, when I got out into
the hall, Pedro, that's one of Dad's pet servants, was scrapping with two
pirate-looking fellows at the head of the stairs. One of them had him by
the throat when I came up."

"And they both got away?" asked the lieutenant.

"Yes, they both got away. They turned and ran down stairs when I came up
and bolted out of the front door, just as if some one stood there holding
it open for them."

"Was the night-lock on?"

"Certainly; it always is at night."

"Couldn't anybody open it from the inside, whether familiar with the house
or not?" asked Ned.

"No; for the night-bolt is controlled by an electric button, which you
have to push before it can be moved from the inside, so no one not
familiar with the house could have opened it."

Nestor glanced at the lieutenant with a question in his eyes, and the
officer nodded. There was little doubt in the mind of either that the
crime had been planned by some one thoroughly conversant with the
pr