“Can’t see a thing,” muttered Aleck.

“Great Scott, look out!”

A series of frantic yells suddenly went up from the occupants of the house-boat; then followed another.

Lights, like great eyes, struggled to show themselves, and, immediately after, the frightened boys saw a confused blur of shadowy masses forging its way toward them. The swish, as the sharp prow cut through the water, reached their ears clearly.

There was no time for action; their voices united in one long cry of alarm.

But it was too late.

A dark mass, cutting the vapor, loomed high up; the eyes shaped themselves into lanterns. There was an instant of breathless suspense.

Then the “Gray Gull” staggered and groaned, and seemed to fairly rise out of the water under the force of the impact. A series of terrific bumps, jolts and grinds carried terror to their hearts, while a hissing, boiling sheet of angry water rising between the two craft swept across the deck.

For an instant, it seemed as if the “Gray Gull” had been struck a mortal blow. Wobbling violently, she swung around with a creaking groan and tugged hard on the anchor chain.

Confused blurs of light and dark, a grim, black hull, slipped by. Shouts rose, then grew fainter; the lanterns became eyes again, and in another instant, all had vanished in the gray gloom of fog beyond.