pring on his back. He saw that man hurl
Frank from the grating.

The stoker uttered a shout and ran toward the foot of the ladder,
expecting to find Frank laying there, severely injured or killed. He was
astounded when he saw the ready-witted youth grasp the grating, swing
in, strike the ladder, cling and slide.

Down Frank came with a rush, but he did not fall. He landed in the
stoke-hole without being severely injured. He was on his feet in a
twinkling, and up that ladder he went like a cat.

His assailant had darted up the ladder above and disappeared. Merry
reached the grating from which he had been hurled, and then he ran up
the other ladder.

He was soon in the engine-room.

In that room there was no excitement. The machinery was sliding and
swinging in a regular manner, while the engineer sat watching its
movements, talking to an assistant. Oilers and cleaners were at work.

"Where is he?" cried Frank, his voice sounding clear and distinct.

They looked at him in amazement.

"What's the matter?" asked the engineer, coming forward.

"I was attacked from behind and thrown into the stoke-hole," Merry
explained. "The fellow who did it came in here."

"Thrown into the stoke-hole?"

"Yes."

"From where?"

"The grating at the foot of the first ladder."

The engineer looked doubtful.

"My dear fellow," he said, "you would have been maimed or killed. You do
not seem to be harmed."

Frank realized that the engineer actually doubted his word.

"He might have fallen," said the assistant; "but it would have broken
his neck."

"I tell you I was attacked from behind and thrown down!" exclaimed
Frank. "I managed to get hold of the ladder and slide, so I was not
killed."

The engineer looked annoyed.

"This is what comes of letting a passenger in here," he said. "It's the
last time I'll do it on my own responsibility. Now if you go out and
tell you were thrown into the stoke-hole, there'll be any amount of fuss
over it."

"I am telling it right here," said Frank, grimly, "and I want to know
who did the trick. Somebody who came from this room must have done it."

"Impossible!"

"Then where did he come from?"

The engineer and his assistant looked at each other, and the former
began to swear.

"What do you think of it, Joe?" he asked.

"Think you made a mistake, Bill; but his story won't go. Nobody'll take
any stock in it."

Frank was angry. It was something unusual for his word to be doubted,