much like to have that. But I need help in getting it off. I do not
intend to steal it, but if it is left here some tramp may destroy it,
and that would be too bad. I intend to remove it, and then hunt up the
owners of this place, and purchase it from them."

"It will be hard to discover who are the owners," replied Mark, "as the
title is in dispute."

"So much the better for me. Will you help me remove the knocker? I will
pay you for your time."

Mark hesitated. He did not like the man's manner, and there was a
shifty, uneasy look about his eyes. Still he might be all right. But
Mark did not like the idea of going into the old house with him alone.
It might be safe, and, again, it might not. But the knocker was on an
outside door. There could be no harm in helping him, as long as it was
outside. The man saw the hesitation in the lad's manner.

"It will not take us long," the stranger said. "I want you to help me
pry off the knocker, as I have no screw-driver to remove it. I will pay
you well."

As he spoke he came nearer to Mark, and the lad noticed that the man's
right hand was held behind his back. This struck Mark as rather
suspicious. Suddenly he became aware of a peculiar odor in the air--a
sweet, sickish odor. He started back in alarm, all his former
suspicions aroused. The man seemed to leap toward him.

"Look out!" suddenly cried the fellow. "Look behind you!"