valves in the outer door and filled the
lock with water. He removed the outer door; and, taking in one hand a
steel-shod twelve-foot pike with a hook on the end, and in the other a
waterproof flashlight, he sallied forth. As he left the shell he paused
for a moment, and then returned and picked up the heavy wrench with
which he had removed the nuts holding the outer door into place. He
fastened the tool to the belt of his suit. Then, with a wave of his hand
toward the detective, he approached the hulk.

The hole in the side was too high for him to reach, but he hooked the
end of his pike in one of the joints of the _Arethusa's_ plates and
climbed slowly and painfully up the side of the vessel. As he
disappeared into the hull, Carnes realized with a sudden start that he
had been watching his friend and neglecting the duty imposed on him of
keeping a sharp watch. He turned quickly to the floodlights and searched
the sea bottom.

* * * * *

Nothing appeared, and the minutes moved as slowly as hours should.
Carnes felt that he had been submerged alone for weeks, and his nerves
grew so tense that he felt that he would scream in another instant. A
sudden thought sobered him like a dash of cold water. If he screamed,
Dr. Bird would take it for an alarm signal and possibly be afraid to
emerge from the vessel. His watch showed him that the Doctor had been
gone for twenty-five minutes and he moved slowly to the radio
transmitter.

"Dr. Bird," he said slowly and distinctly, "you have been gone nearly
thirty minutes. Nothing alarming has appeared but I will feel better
when I see you coming back."

He glued his eyes on the opening in the ship's side and waited. Five
minutes passed, and then ten, with no signs of the Doctor. Carnes moved
again to the receiver.

"It has been over half an hour. Doctor," he cried in a pleading voice.
"If you are all right, for God's sake show yourself. I am frantic with
worry."

Another five minutes passed, and the sweat dripped in a steady stream
from the detective's chin. Suddenly he gave a sob of relief and sank
back against the side of the globe. A bulky figure showed at the edge of
the hole, and Dr. Bird climbed slowly and heavily out of the hold and
dropped to the sea bottom. He lay prone for a moment before he rose and
made his way with evident effort toward the sphere. He entered the
compartment and with a heroic effort lifted the outer door into place,