"He's not the only prisoner we've got," went on Matt. "Fingal is below!"
"Bully! We want him. Perhaps we had better take all your prisoners, eh?"
"We'd like to get rid of them."
"Well, stay where you are and we'll send a boat."
"You mustn't let Pedro go, Matt!" exclaimed Ysabel.
"That's so," said Matt. "Suppose you go down, little girl, and set Pedro free. Send him to the torpedo room and tell him to wait there until the cruiser is gone."
Ysabel vanished into the tower.
Meanwhile the cruiser had been clearing away a boat. When she hove alongside the submarine, Carl Pretzel, wearing a grin that could have been tied behind his ears, was sitting in the bow.
"I vill go mit you part oof dis groose, anyvay," he whooped. "Drow some lines so dot I may come apoard."
A line was thrown and Carl was heaved from the rocking rowboat to the submarine's deck. He threw his arms around Matt and almost hugged him over the side of the Grampus.