ead a paper here. I'd like to see
what's inside that thing myself."

"Do you know anything about electricity or telephony?" asked Drew, as
he turned the hard-rubber receiver in his hand and stared at the
listening end.

"Very little, Inspector. But fire-arms are in my line and that seems to
be one."

The detective nodded. "It's one, all right," he said, holding it out
with a steady hand. "Looks harmless, don't it? Two binding-posts on one
end. A rubber cap on the other. Notice that diaphragm."

Nichols took the receiver and squinted at the rubber cap. "By George!"
he said. "This is odd. There's a tiny hole drilled or punched in the
center. It's about the same size as the bore of a twenty-two caliber
revolver."

"Look at your hands!" said Drew. "What the devil," he added with
dawning conviction. "Say, Delaney, do you remember that spot of black
under my left ear. The one you noticed after we left yesterday morning?
The----"

"Sure, Chief. That's where you got the smut--from that receiver!"

"I got it when I picked up the telephone in the library downstairs and
tried to get Central. Do you remember how long she took? This is the
same receiver in all probability. The trouble-hunter removed it from
the library connections, loaded it, and brought it up here. It looks
like any ordinary receiver. The telephone company have some with
binding posts and some without. This is an earlier model."

"The spot of black was from the first discharge when Stockbridge was
killed!" exclaimed Delaney.

Drew ran his fingers around the inner rim of the rubber cap. He held
them up. "See!" he exclaimed. "No wonder my neck was marked. That
settles that mystery, Delaney. If we had any brains at all we would
have connected the soot and the telephone. If we had done that we'd
have solved the case early this morning, or yesterday morning. It's
after one, now!"

"This hole," said Nichols, "was the only thing in the whole dastardly
scheme that could have been seen. It's the size of the end of a lead
pencil. Funny you didn't notice it?"

"I looked everywhere but there," admitted Drew. "The receiver hangs
with the diaphragm end down. That's the reason I didn't see it.
Well--there's always a reason," he added. "Now, Delaney, fetch me that
trouble-hunter's satchel. We'll see what this pistol is made of and how
it is made. I venture to say that it is simple."

Delaney awoke from his stupor and lifted a rug which he tossed over the
body of C