the arm.

"Hi! what's this, a hold-up?" cried the man, evidently frightened.
"Let go of me!" And he tried to pull away and then attempted to draw a
revolver from a hip pocket.

"Stop! I am not going to hurt you," was the calm reply from the
detective. "I want to talk to you, that's all."

"Really?" came with a sneer. "A fine time of night to hold a man up.
Be quick, for I am in a hurry."

"I want you to explain several things to me," went on Adam Adams calmly.

"Explain? To you?"

"That is what I said. You can take your choice. Either explain or
consider yourself under arrest."

"Eh? Say, are you crazy?"

"Not at all."

"An officer of the law, I suppose."

"I am--in a way."

"Working on this Langmore affair?"

"Yes."

"Have you been following me?"

"I've done more than that--I've been watching you."

"What! How long?"

"Quite a long while. I saw you in the library, twice, and down to the
brook."

The man started and was evidently much put out. Then he forced a smile
to his face.

"Much obliged for playing the spy," he murmured.

"Down at the brook you had a pair of Miss Langmore's shoes. What were
you doing with them?"

"Did you see me with the shoes?"

"I did, and I saw you with the silk shirtwaist."

"Ah! Anything else?"

"I saw you at the safe in the library of the mansion."

"When, now?"

"Now and some hours ago. You may as well make a clean breast of it."

"I will, If you will tell me who you are."

"I am Adam Adams, of New York City."

The strange man let out a hissing sound between his teeth. Then of a
sudden he gave a wild, unnatural laugh.

"Shake hands, Mr. Adams," he said, putting out his hand. "I know you
by reputation even if not personally. You see, your reputation is so
much larger than my own." He laughed again, a sound which grated on
the detective's nerves. "I am John S. Watkins, of Bryport. I am
connected with the United States secret service."

CHAPTER VIII

WHAT CEPHAS CARBOY SAW

There was a brief pause after the man from Bryport made his
announcement. Adam Adams tried hard to see his face clearly, but in
the gloom this was impossible.

"Perhaps you do not believe me," said John Watkins. "I can easily
prove what I say."

"Why shouldn't I believe you?"

"Because you were on the point of arresting me, which proves that you
took me to be--something else."

"How long have you been connected with the secret service?"

"Abo