He could hear Cassidy getting up, and his exclamation of relief was loud and hearty.
"Now, by thunder," growled Cassidy, "we're havin' our innings. I reckon Jurgens'll find that his high-handed game o' his ain't all one-sided. I'll go turn on the lights, Motor Matt," and Cassidy could be heard leaving the room and passing into the corridor.
Matt and Carl groped about until they had found the other two prisoners, and while they were freeing them the lights were suddenly turned on.
"I'm Burke," said one of the men.
"Harris, that's me," said the other.
"How many men did Jurgens have on the submarine with him?" asked Matt.
"The' was four of 'em," replied Harris, standing erect and rubbing his cramped limbs. "The three that come first an' pulled the wool over Cassidy's eyes with that letter, an' then Whistler. That's all of 'em, Motor Matt."
"Jurgens and Whistler have been captured," went on Matt, "and one of my friends has another in the room below the conning tower. That leaves two more. Have you any idea where they are?"
This question was answered by a terrific clamor from some point in the forward part of the ship. Above the noise broke the sudden report of a revolver, echoing loudly between the steel decks and bulkheads.
"Here they are, men!" came the voice of Cassidy, husky and breathless as though he was fighting. "Here's t'other two of 'em in the torpedo room, tryin' ter get out the bow port."