"Something in that sick man's face tells me he has not spoken all the truth. We must have it out of him," said our hero.

But at that moment a mournful howl came from above.

Rushing to where their arms were stacked, Bob and Jack seized each a rifle and made their way on deck, not heeding, in their excitement, a cry not to fire from Horton, the sick man.

On lifting their eyes aloft they beheld a singular-looking object gazing at them over the edge of the foretop.

It appeared to be some huge animal, though of what kind they could not make out.

Scarcely waiting to consider what they were doing, Bob and Jack prepared to fire.

A wild shriek echoed along the deck.

"Stop that noise!" cried Bob, glancing round and seeing that Horton had managed to ascend the companion ladder.

Bob had thrown up his rifle to his shoulder, when the weak voice of the sailor arrested him in the act of firing.

"For heaven's sake, sir, don't fire! It's murder, nothing else."