At this moment Jack and Frank sprang into the room. They saw Lord Hastings confronted by two enemies and they acted instantly and before the Germans could do so.
The revolvers of both lads spoke simultaneously and both Germans dropped to the floor.
Jack sprang back to the door.
"Stand guard there, men!" he cried. "There may be more of them."
He jumped back to Frank's side again, fearing that one of the fallen men might arise and return to the fray. But these fears were groundless. All four were beyond human aid, as Lord Hastings found after gazing at each sharply.
"Poor fellows," he said sorrowfully, "but it was their lives or ours, and they wouldn't yield. Oh, well——" he broke off with a shrug of his shoulders and turned to the lads.
"Search the vessel," he commanded. "There are probably others aboard."
Jack and Frank hurried away in response to this command. They went through the submarine from stem to stern, but nowhere were they able to find another living soul.
"Looks like those were the only ones aboard," remarked Jack.
"It does," agreed Frank. "Maybe the men in the motorboats were part of their crews and they have been lying about here all these days waiting for them to return."