ch which he planned to
use.

Out into the river they sailed, Eva at the wheel, while Locke busied
himself over the sputtering engine. Soon they arrived at a spot which
was suitable for the test of the suit.

Locke had brought along the full equipment, and, while Eva took charge
of the air-pump, Locke donned the diving-suit. Soon all was ready and
Locke descended over the side, after carefully instructing Eva in each
detail. Eva started pumping, while with her other hand she carefully
paid out the air-line and signal-cord.

But in their close attention to the task in hand, neither had noticed a
low, knifelike launch that had followed them and that was now hovering a
short distance off.

Locke was now walking over the shell-strewn bottom, examining curious
objects here and there. The tide was setting in strongly and at times it
was with difficulty that he kept his feet.

He had become satisfied that this particular suit filled all the
requirements of a first-class diving-suit, and he was about to try its
special, self-liberating feature, when his attention was arrested by a
vague mass which seemingly moved against the current.

This was so extraordinary that his first thought was of a shark. He
stopped in his tracks and became motionless, for it is a well-known fact
that these sea tigers rarely see an object unless it is in motion.
Still, the vague form slowly took on more distinctness as in its course
it gradually drew nearer to him. It was then that Locke was almost
overcome with surprise. For there, groping his way toward him, was a
diver, like himself.

What was this strange being doing there on the bottom of the sea? Whence
had he come? Locke could not guess. For, like Eva, he had not noticed
the other launch. It seemed impossible to him. Still, to him, apart from
curiosity at the appearance of the other diver, the incident had no
other interest. What had he to fear from any man at the bottom of a
peaceful harbor? Locke moved nearer.

The stranger allowed him to approach, stopped, even, as though he were
himself amazed at Locke's appearance, and Locke made gestures to
reassure the man of his good intentions.

Locke was quite close now, and through the glass gate in the other's
helmet he could see his eyes. But in those eyes he could see no
responding friendliness. There was a murderous hate instead. He tried to
step back and place himself in a position for defense, but he was too
late. For, with a movemen