"We are looking for a spy," replied the other imperturbably, and addressed himself to an examination of the things he had taken from Stewart's pockets--his penknife, his watch, the contents of his purse, the papers in his pocket-book. He even placed a meditative finger for an instant on the two tiny metal clips which had come from the Cook ticket. But to reconstruct their use was evidently too great a task even for a German police agent, for he passed on almost at once to something else. "Very good," he said at last, pushed the pile toward its owner, and opened the passport, which he had laid to one side. "That passport will tell you that I am not a spy," said Stewart, putting his things angrily back into his pockets. "That, it seems to me, should be sufficient." "As far as you are concerned, it is entirely sufficient," said the other. "One can see at a glance that you are an American. But the appearance of Madame is distinctly French." "Americans are of every race," Stewart pointed out. "I have seen many who look far more German than you do." "That is true; but it so happens that the spy we are looking for is a woman. I cannot tell you more, except that it is imperative she does not escape." "And you suspect my wife?" Stewart demanded. "But that is absurd!" He was proud of the fact that he had managed to maintain unaltered his expression of virtuous indignation, for a sudden chill had run down his spine at the other's careless words. Evidently the situation was far more dangerous than he had suspected! Then he was conscious that his hands were trembling slightly, and thrust them quickly into his pockets. "The fact that she joined you at Aachen seemed most suspicious," the inspector pointed out. "I do not remember that you mentioned her during your conversation with the ladies in the train." "Certainly not. Why should I have mentioned her?" "There was perhaps no reason for doing so," the inspector admitted. "Nevertheless, it seemed to us unusual that she should have come back from Spa to Aachen to meet you, when she might, so much more conveniently, have gone direct to Brussels and awaited you there." "She has explained why we made that arrangement." "Yes," and through half-closed eyes he watched the smoke from his cigarette circle upwards toward the lamp. "Conjugal affection--most admirable, I am sure! It is unfortunate that Madame's appearance should answer so closely to that of the woman for whom we are searching. It was also unfortunate that you should have met at the Kölner Hof. That hotel has not a good reputation--it is frequented by too many French whose business is not quite clear to us. How did it happen that you went there?" "Why," retorted Stewart hotly, glad of the chance to return one of the many blows which had been rained upon him, "one of your own men recommended it." "One of my own men? I do not understand," and the officer looked at him curiously.