After about twenty minutes' wait Jack heard the sound of approaching footsteps outside and the clink of accoutrements that denoted the approach of an armed body of some sort. The sentry at the door came to attention and saluted the leader of a file of some ten men who halted and set their guns down with a thud that Jack could plainly hear in the wireless station. There was a short exchange of words at the door and then the commander of the detail stalked over and took a look at the prisoner. Jack looked up to see before him a brawny German in the uniform of a lieutenant of the Imperial German Navy.
"Who are you?" the officer demanded.
Jack shook his head in reply.
"How did you get here?" came the command more sharply.
Still Jack kept silence.
"Search him!" ordered the officer, and after a search that revealed nothing, he added in German:
"Take him away—-we'll go into his record later. He's only a boy anyhow, and boy spies are not worth bothering about in this man's war."
Jack was marched off to the canal bank and, following the towpath for a time, the party reached a small fishing village of not more than thirty or forty huts built upon the banks of a stream that Jack realized immediately was the same waterway up which he had made his way to the wireless station. Now he was a mile or more inland from the lagoon and the seacoast.
In the water, moored alongside a wharf, was a huge submarine—-one of the latest type of U-boat. This, no doubt, was its hiding place and the rendezvous of other U-boats. Like a flash it occurred to the American boy that he had penetrated, or rather had been escorted, into the heart of one of the submarine bases.
"If I ever get out of this mess," he resolved to himself, "I'll put
Uncle Sam wise to this rat hole."