and your heart action is not right
just now. My mind is a blank, and my heart is as sound as a bullet! I'm
just the one for the job!"

As if the matter were understood, Jimmie began divesting himself of his
clothing. He deposited his jacket on the locker beside Ned.

"Harry," he said, turning to his chum, "will you see that the torpedo
tube is connected up and in working order? You might try a discharge for
practice. We can spare a little of this air!"

By the time Jimmie had stripped and secured a knife to a belt about his
waist, Harry pronounced the tube ready for operation.

"Now, fellows," said Jimmie, shaking hands with his chums, "there's about
one chance in a million that I won't get through this all right. If you
are not up to the surface in five minutes, you may know that I've failed.
Then you'd better send out another lad!"

"Me next!" shouted Jack, beginning to remove his shoes.

Harry was peering from the heavy glass protecting the forward porthole.
As Jimmie stepped forward to enter the torpedo tube, Harry held up a
warning hand. He turned an anxious face to his friends.

"There's something outside here!" he announced in an anxious tone. "I saw
it once, but didn't get a clear view!"

"What did it look like?" asked Jimmie. "Is it alive?"

"I'm not sure, but I think it's another submarine!"

"Probably the real 'U-13' come up to look us over. Never mind those
fellows. I'm going ahead and cut this wagon loose!"

"Wait a minute!" cried Ned. "I see the craft over here to starboard. It's
a peculiar vessel, too! I think I see a man!"

"I see him, too!" declared Frank from a porthole a short distance aft.
"Do you suppose he's trying to get us to descend again?"

"Maybe that's it! Let's try it, anyway!" offered Harry.

"Go ahead!" agreed Ned in a tone that showed he was again taking heart.
"Let's act on the suggestion. We can try our scheme later!"

Harry's hand had already found the levers. In a moment the ballast tanks
were being filled with water. Gradually the vessel sank.

As the light grew more dim at the increased depth, Jimmie declared he
could see the other vessel descending at about the same speed.

Presently the two craft were at the limit of their travel. The visitor
rested on the deck of the Wanderer, while the 'U-13', in which the boys
were imprisoned, hung again at an angle from the line.

Directly the lads saw the figure that had formerly attracted their
attention. It was climbing