should an enemy appear.

Again a bell tinkled in the engine room, following an order from the
commander of the _Queen Mary_.

The great engines stopped and became silent.

"Cut off all lights!" was the next command.

A moment later the great ship was in darkness.

Frank and Jack, in their quarters, were awakened by the sounds of
confusion above. All hands had not been piped on deck, so most of the
men still lay asleep, unconscious of what was going on above, but the
two lads, dressing hurriedly, made their way on deck. They walked
forward, toward the bridge.

All was dark and it was this that told Frank and Jack that something
was going on.

"Wonder what's up?" said Frank.

"Airship, I guess," was the reply. "Can't see any other reason for
extinguishing all lights."

Near the bridge the lads stopped and waited to see what would happen.
All was quiet aboard. Not a sound came from the officers or the men on
deck. Then Captain Raleigh commanded:

"Try the forward searchlight there. See if you can pick her up!"