When the woman at Mrs. Corliss’ had disclosed herself as an enemy, Ruth had balanced the harm the woman might do to America against the harm she, herself, might do Germany, and Ruth had decided, rightly or wrongly, to remain quiet. Now she could not do so. A German spy in Chicago was a distant, only indirectly dangerous person; a spy in Paris did most direct things--such as setting colored lights at the bottoms of chimneys to guide the great black-crossed _Gothas_ which bombed Paris by night, blowing down those buildings in the ruins of which Ruth had seen men frantically digging by the early morning light; they did things such as ... Ruth did not delay to catalog in that flash the acts of Germans in Paris. She knew that man must be arrested at whatever cost to herself. She started after him down the Rue St. Jacques in the first spur of this impulse. Fortunately, after leaving her, he did not gaze back, but proceeded alertly along the street. A man and a woman spoke to him; he bowed. Another passer-by bowed to him with the deference shown a gentleman of importance and position. And Ruth slowed her pursuit and followed a little distance behind him. He turned to the Boulevard St. Michel, where others bowed to him, crossed the boulevard and went into the Ecole de Médecine. Ruth halted a man who had spoken to him and inquired, please, the name of the gentleman who had just passed. The Frenchman informed politely, “Monsieur de Trevenac.” “The entire name, please?” Ruth pressed. “Monsieur Louis de Trevenac,” the name was repeated as of one well known. Ruth proceeded to the door of the Ecole de Médecine, where inquiry confirmed the name; M. de Trevenac had just entered. Ruth abandoned the pursuit. She was shaking with excitement under her trim, khaki uniform and cape; but coolness had come to her--coolness and that calm, competent thought which always succeeded the irresponsible impulse with her. The German agent, M. Louis de Trevenac, was not trying to escape from Paris; his business, undoubtedly, was to remain here, and not in hiding, but prominent and well known. If she accused him to a gendarme the alarm would go at once to his confederates; it would be the stupidest and clumsiest action she could take. Now that she knew him, she could move most effectively by indirection; she need not betray herself at all, either to the French or to the Germans. She returned across the Seine and went to her work while she thought it out. She could accomplish her purpose partly, perhaps, through Hubert Lennon. She might accomplish it more safely through the aid of other men whom she now knew; or through Mr. Mayhew. But she could accomplish it best through Gerry Hull. Accordingly she telephoned to Hubert that afternoon to meet her at the _pension_ as soon as possible; and when he came, she asked him if he knew where Gerry Hull was. He was in Paris, Hubert had to confess; he had been in Paris for two days.