"Not at all, Billy," said the other, trying to act as though he might be telling them something of small importance. "I watched while I was sheltered under the plane, and twice I saw it shake a little as though some one might be holding the door ajar so as to hear better."
"Door!" echoed Billy helplessly, as though more puzzled than ever.
"The door of the empty locker we thought we might need for storing things away, but which has never been used," Frank explained.
"Gee whillikins! now I understand what you mean, Frank," said Billy. "There is plenty of room in that locker to hold a man curled up."
"Popguns and pyramids, but how could he ever get there when we've been sitting around all morning?" asked Pudge, in a hoarse whisper.
"Only in one way," Frank told him. "Before they left here last night they must have fixed him there in the locker, believing we'd be back again sooner or later, when some information of value might be picked up."
"Oh! my stars, Frank," Billy ejaculated huskily. "What if, after all, he's heard enough talk here to guess about that big raid?"
"It's true that we've been pretty careful," he said, "and most of the time just whispered while we talked about it; but all the same a man with the ears of a spy might have picked up enough to arouse suspicions, and once that's done the rest would come easy."
"What can we do about it, Frank?" asked Billy.
"Our good friend, the Major, has extended the invitation to us so that in a way I feel we're responsible for the secret being kept," Frank went on to say, as though he might be revolving certain conditions in his mind before deciding.
On hearing him say that Billy began to work the muscles of his right arm, at the same time opening and closing his fingers, as though eager to clutch something.
"I agree with you, Frank," he hastened to say. "The great secret has been placed in our keeping, and for one I would feel pretty small if it leaked out through any fault of ours. We've got to cage that spy as sure as you live."
"Punkins and partridges, that's right!" muttered Pudge, who, while not as a rule pugnaciously inclined, could nevertheless assume what he was pleased to call his "fighting face" when occasion arose.
"I'm glad to find both of you are of the same mind," Frank said. "The only question is to decide what our plan of campaign shall be."