"A gun!" cried Jack.
"No!" said Fritz. "It isn't possible. We are mistaken."
"Listen!" answered Jack, scarcely breathing.
A second detonation rang through the air, and then after an interval of a minute a third resounded.
"Yes, yes!" Jack insisted. "Those are cannon shots all right."
"And they came from the east," Fritz added.
Was it really a ship, passing within sight of New Switzerland, that had replied to the double discharge from Shark's Island, and would that ship steer her course for Deliverance Bay?