"That's a slang word for diamonds," suggested Ned.

"So it is. In that case, dad, I think we have nothing to worry
about. Those fellows must be going to commit a diamond robbery or
perhaps it has already taken place."

The inventor seemed relieved at this theory of his son. His face
brightened and he said: "If they are going to commit a robbery,
Tom, we ought to notify the police."

"But if they said that 'Murdock,' whoever he is, had the sparkler
and was trying to get away with it without giving them their
share, wouldn't that indicate that the robbery had already taken
place?" asked Ned.

"That's so," agreed Tom. "But it won't do any harm to tell the
hotel detective that suspicious characters are around, no matter
if the has been committed. Then he can be on the lookout. But I
don't think we have anything to worry about, dad. Still, if you
like, I'll take a run down to the house to see that everything is
all right, though I'm sure it will be found that we have nothing
to be alarmed over."

"Well, I will be more relieved if you do," said the inventor,
"However, suppose we have a good supper now and you boys can stay
at the hotel to-night. Then you and Ned can start off early in
the morning."

"All right," agreed Tom, but there was a thoughtful look on his
face and he appeared to be planning something that needed careful