For the first time Harry Hazelton felt positively dismayed. He saw the
long, massive arms moving, looking like a powerful ape's arms. There could
be no doubt that the unknown was ready for a spring.

Harry did not retreat. Where could he run to? Only a few yards could he
go out towards the end of the wall. Then, if he wished to continue his
flight he could only take to the water.

Only a glance was needed at the bulky, powerful frame of the unknown to
make it appear certain that the latter could swim two rods to the young
engineer's one.

Harry decided instantly to stand his ground and to make the most valiant
fight possible on so slippery a footing as that presented by the top of
the retaining wall.

"Ha, ha! Ho, ho!"

It was as though the black unknown sought to terrify his intended victim
with his repetitions of that harsh, discordant laugh. Harry braced himself
and waited.

Then, off shoreward, came the sound of "put-put-put." The motor boat,
"Morton," was putting out at last.

"If I can keep this fellow busy for a few minutes, I can have all the help
I want," flashed through Hazelton's mind. So he opened his mouth, raising
his voice in a long, pent-up hail.

"R e---e---e a d e! To---o---o---om R e a d e! Quick! Hazelton!"