dden shock of his plight.

"Or maybe the impact of the projectile stunned him!" Tom surmised.

Bud began groping his way upward just as Tom came alongside of him. Tom
grabbed him as best he could, hooking onto his belt. At the same time,
the young inventor inhaled deeply, yanked out Bud's useless mouthpiece,
and inserted his own in its place.

Bud's eyes glowed with gratitude.

"We'll have to get topside fast," Tom thought, "even though it means
risking the bends."

He stroked upward and they shot toward the surface. Bud assisted to some
extent, partly revived by the gulp of air.

As they rose, fathom by fathom, their progress seemed to grow
maddeningly slower. Tom had to let air bubbles escape constantly from
his mouth. As the pressure decreased, due to the lessening depth of the
water, the air in his lungs expanded and he was forced to breathe out.

Tom noticed with dismay that Bud was not responding very well, his
feeble strokes were jerky and uncoordinated. "Must've lost pressure too
fast when his tank was hit," Tom realized.

The water was growing greener and brighter now as they neared the
sunshine. The _Sea Hound_'s shadowy outline loomed just above. With a
last desperate burst of strength, Tom lunged upward and they broke
water.

"H-h-help!" Tom gasped.

There was no need for the cry. Hank and his crew, on the seacopter's
forward deck, had already grasped the situation. Strong arms reached out
and hauled the two boys aboard.

Both of them were shivering and writhing in pain, only half conscious.

"They have the bends!" Arv Hanson cried in alarm. "Signal the _Sky
Queen_ to drop a sling!"

The boys' masks were ripped off. Within moments, Bud had been tightly
secured to the sling, which was reeled back up into the plane. Tom
followed in a few minutes. Doc Simpson took charge of the patients
immediately. After a quick examination, he had the boys placed in a
small decompression chamber in the _Sky Queen_'s sick bay.

"How are they?" Hank asked anxiously as he peered through the window of
the chamber. The medic had given Bud a sedative and he was already fast
asleep. Tom remained awake.

"Aside from the pain, not in too bad shape," Doc Simpson replied.

It turned out that Tom's case was not so serious, but Bud had to stay in
bed. With Tom, it was only a matter of decompression and he soon was up
and about.

Chow, in a chef's cap, with an apron around his paunchy stomach, had
come stomping in has