“Maybe they wanted to hold them out and get the best offer they could for our property,” suggested Charlie.

“Maybe,” assented Blake.  “Whatever their game was,” and he spoke in a low tone which could not carry to the two plotters who were walking ahead with the German captain, “they went to the hut to get the films they had left there.  And as luck would have it, we came on the scene at the same time.”

“I wish we’d been a little ahead of time,” complained Macaroni.  “Then we might have gotten back with our films.”

“No use crying over a broken milk bottle,” remarked Joe.

“That’s right,” Blake said.  “Anyhow, there we were and there Secor and his German friend were when the others came and——­”

“Here we are now!” finished Joe grimly.

And there, indeed, they were, prisoners, with what fate in store none of them could say.

Suddenly from the darkness a sentinel challenged in German, and the captain of the little party answered, passing on with the prisoners.

A little later they turned down into a sort of trench and went along this, the boys being so placed that each walked between two Germans, who carried their guns with bayonets fixed, as though they would use them on the slightest provocation.  But Blake and his chums gave none.

And then, making a sudden turn, the party came to what was evidently an outpost of importance.  There were several large underground chambers, fitted up with some degree of comfort and a number of officers and soldiers about.  Some were eating, some smoking, and others drinking, and still others sleeping.  In one room could be seen a rough table, laden with maps and papers, and there were many electric lights, showing to what degree of perfection the German military system was carried out at this point.  A portable dynamo and gasolene engine probably furnished the current.

The captives were halted, and a brief talk in German took place between the captain and the officer to whom he reported.  What was said Blake and his chums could not, of course, hear, nor could they have understood had they heard.

A little later, however, they were ordered to march on, and then were shown into an underground room, none too clean and quite dark, and the door was banged shut on them.  Just before this they had seen Secor and Labenstein go off in another direction, still carrying the boxes of films.

The echoes of the retreating footsteps of the men who had thrust them into their prison soon died away, and the boys were left to themselves in a veritable cell that was unpleasantly dirty and dark.

“Whew!” whistled Joe, after a moment of silence.  “This time we certainly are up against it!”

Suddenly a light flashed in the darkness.

“What’s that?” asked Joe sharply.

“I want to see what sort of hotel accommodations they’ve given us,” was Blake’s grim answer, as he flashed his pocket light about.  The Germans had not taken those from the boys, and they were soon inspecting their prison.