Straight to his captain Frank hastened and told his story. He had not finished before the captain sent out hastily for others higher in authority. Then Frank, often interrupted by excited questioning, narrated every detail of the night's discovery. The phial was handed over to the chief medical officer, and Frank, after hearty commendation, was bidden to hold himself ready for call at a moment's notice. He hurried off to the barracks, where his comrades were eagerly awaiting him. To them he poured out all he knew and suspected. That night and the next day witnessed busy scenes at the headquarters of the medical staff. The contents of the phial were analysed and justified Frank's suspicions. A force was organized in which the Army Boys were included to seize the arch-plotter. It would have been possible to have entered his house from the front, but the broad street on which it stood was a thoroughfare thronged with people at night, and in order to avoid possible riot and attempt at rescue it was deemed best to enter from the trap door in the alley. As soon as it was fully dark, the detachment was set in motion. Sentries were posted on either side of the alley to prevent any one from entering, and one by one the arresting party swept down through the passage from the alley and they made their way, with Frank as guide, to the oaken door. Here they paused and listened. Far from being empty, as on the night before, there were sounds in the room that amounted almost to tumult. Loud exclamations were interspersed with bursts of laughter. The main note seemed to be approval. Some one who aroused the enthusiasm of his hearers was speaking. Slowly, very slowly, Lieutenant Winter, who was in charge, drew the door open by imperceptible degrees. It was the doctor himself who was holding forth, almost with frenzy. His gestures were wild and his words came so fast as to make his speech almost incoherent. But the listeners caught enough from that wild torrent of words to know that their darkest suspicions were more than justified. The man was gloating over his wickedness, over the deaths that had already resulted, and the deaths he hoped to cause through his diabolical discovery. He stopped at length, and others in the party had their turn. Here was something beyond what the raiding party had looked for. They had stumbled upon a nest of conspirators who, in their way, as the doctor in his, were deadly enemies of society in general and the Americans in particular. Through this secret passage into the alley, for how long none of them knew, these desperate men had been going to and fro, avoiding attention and hatching in the doctor's office a plot that had kept the entire zone of the American Army of Occupation in a state of unrest. The proof was all-sufficient, and the conspirators were weaving the noose for their own necks. The lieutenant lifted his hand, swung the door wide open, and, followed by his men, rushed into the room. CHAPTER XXV