Now Reade had leisure to wonder how matters had gone with Harry Hazelton.

"Of course that threatening figure Harry saw behind him was an imaginary
one," Tom said to himself, but he felt uneasy nevertheless.

A few moments later Reade clutched at one of Evarts's arms.

"Did you hear that, man?" the young engineer demanded.

"Hear what?" Evarts wanted to know.

"It sounded like a yell out there yonder," Tom rejoined.

"Didn't hear it, Mr. Reade."

"There it goes again!" cried Tom, leaping up. "Some one is calling my
name. It must be Harry Hazelton, and he must want help. Conlon, slam it
to that engine of yours!"




CHAPTER III

VANISHING INTO THIN AIR


Left by himself Harry had stood, at first, motionless, or nearly so. He
strained his hearing in trying to detect any unusual sound of the night,