the heavy chisel into the crack between
the door and the jam, and then, standing off to get a wider swing with
the hammer, struck it sidewise.

A panel of the door cracked and loosened. Two more attempts and the
panel fell in strips to the floor. Thus given something for a grip-hold,
the captain, who was a massive man, took hold with both hands, put his
right foot against the wall, and, with one tremendous tug, into which
he threw the whole weight of his body, brought the entire door from its
hinges.

The captain went staggering backward from the force of his effort and
the weight of the door.

The unconscious form of Lieutenant Mackinson tumbled out upon the floor.
His face was almost blue from suffocation.

The captain sounded three short, sharp blasts upon a whistle which he
had taken from his pocket, and two oilers came running to the spot.

"Help us carry this man to fresh air immediately," he ordered. "He has
been overcome."

With one of the oilers carrying the lieutenant by the feet, and the
other man and Slim at either shoulder, the unconscious young officer was
carried up flight after flight of steps until, the captain leading the
way, they arrived at the promenade deck.

A seaman was dispatched for the ship's surgeon, who arrived a few
minutes later to find the first-aid efforts of the four men just
bringing Lieutenant Mackinson back to consciousness.

As the physician forced some aromatic spirits of ammonia between his
lips the lieutenant opened his eyes and gazed about vaguely.

"What's the matter?" he asked weakly; but before anyone could answer he
had relapsed again, and there was another wait of several minutes.

But this time the lieutenant's mind was clearing.

"Somebody shoved me--in that closet," he gasped, "and then--slammed
and--locked--the door."

He recognized the captain and the doctor. As his eyes closed again he
added, in an almost inaudible whisper: "I was getting too close on
somebody's trail."

The captain looked at the ship's doctor significantly and dismissed the
two oilers with instructions to return to their duties.

"Found him locked in a small compartment down near the auxiliary engine
room," the commander said briefly. "Hotter than blazes, and no air
whatever where he was. He made his whereabouts known by tapping a
message on a steam-pipe."

"H'm," said the doctor, whose youthful appearance might not give a
stranger a proper measure of his long and varied experience