"Gone!" cried Frank.
"Vanished!" panted the professor.
"An' now Oi suppose ye'll say it wur no ghost?" gurgled Barney.
It was extremely dark beneath the shadow of the cypress trees, and not a sign of the mysterious canoe could they see.
"It is evident he did not care to have me send a bullet whizzing past his ears," laughed Frank, who did not seem in the least disturbed.
"What are your nerves made of?" demanded Professor Scotch, in a shaking tone of voice. "They must be iron!"
"Hark!"
Frank's hand fell on the professor's arm, and the three listened intently, hearing something that gave them no little surprise.
From far away through the night came the sound of hoarse voices singing a wild, doleful song.
"Hamlet's ghost!" ejaculated the professor.