"Well," said Frank, "we have followed him this far. We might as well stay for the finish, whatever it may be." "All right, then. Let's see if we can get in." Two doors away from the tobacco shop a narrow alleyway led toward the rear. Making certain that no one was watching them, the boys slunk into this and made their way to the rear of the shop. Here they looked around carefully. Not a soul was in sight. Near by stood a barrel. Frank dragged it close to a little window in the room behind the shop and while Jack stood on guard, Frank climbed up and peered in. The blind was drawn, but it did not reach the bottom by an inch. The opening was just level with Frank's eyes when he stood upon the barrel. He looked in, exercising the greatest care to avoid detection. His eyes beheld a strange sight. Gathered about a little table in the room were four men, their heads close together, scrutinizing an object that lay between them. At first Frank could not make out what it was, but as one of the men leaned back in his chair, Frank, over his shoulder, recognized it. Quickly he jumped from the barrel and whispered to Jack. "You were right." "Right? How?" asked Jack. "Bomb," replied Frank briefly. Jack stepped back in surprise. "A bomb!" he exclaimed. "Yes," Frank repeated, "a bomb. They are examining it, or something. I can't tell just what." "Couldn't you hear what they were saying?" "No; the window is closed." "What do you suppose they intend to do with it?" "You know as much about it as I do." "Well, then, what are we going to do about it?" "That's the question. I suppose we might call the police, but if we did the chances are they would find nothing when they entered the place; or we might notify the military authorities, but the conspirators would be gone before they arrived." "Haven't you an idea?" "Yes, I have an idea, but it involves considerable risk." "Since when have you become so cautious? Risk didn't use to bother you." "It wouldn't now, if I were sure we had a chance of success." "What's your plan?" "There is but one way I can think of by which we can overhear the conversation in that room. It is impossible for us to get in this way without being seen, and the only other entrance, so far as I know, is through the tobacco shop. Therefore we shall have to go in that way." "And I suppose the shopkeeper will stand right there and let us do it," said Jack with some sarcasm. "We'll have to tie him up before he can give the alarm." "Suits me," said Jack. "I am willing to take a chance if you are. Come on." Quickly the lads made their way back to the street, and once more entered the store. The shopkeeper recognized them instantly by their uniforms, and approached. "These cigarettes you gave me," said Frank, "are no good. I want another package." "What's the matter with them?" demanded the storekeeper. "Let me see them."