This yellow horse assumed gigantic proportions in Licquet's imagination; it haunted him day and night, and galloped through all his nightmares. A fresh search at Tournebut proved that the stables contained only a small donkey and four horses, instead of the usual five, and the peasants said that the missing beast was "reddish, inclining to yellow." As the detective sent Real all of Mme. de Combray's letters in his daily budget, they were just as much agitated in Paris over this mysterious animal, whose discovery was, as the Marquise said, the clue to the whole affair. Whom had this horse drawn or carried? One of the Bourbon princes, perhaps? D'Ache? Mme. Acquet, whom they were vainly seeking throughout Normandy? Licquet was obliged to confess to his chiefs that he did not know to what occurrence the story of the horse referred. He felt that the weight attached by Mme. de Combray to its return, increased the importance of knowing what it had been used for. "This is the main point," he said; "the horse, the saddle and bridle must be found." In the absence of Lefebre, who could have solved the enigma, and whom Caffarelli had not decided to arrest, there remained one way of discovering Mme. de Combray's secret--an odious way, it is true, but one that Licquet, in his bewilderment, did not hesitate to employ. This was to put a spy with her, who would make her speak. There was in the Conciergerie at Rouen a woman named Delaitre, who had been there for six years. This woman was employed in the infirmary; she had good enough manners, expressed herself well, and was about the same age as Mme. Acquet. It was easy to believe that, in return for some remission of her sentence, she would act as Licquet's spy. They spoke of her to the Marquise, taking care to represent her as a royalist, persecuted for her opinions. The Marquise expressed a wish to see her; Delaitre played her part to perfection, saying that she had been educated with Mme. Acquet at the convent of the Nouvelles Catholique, and that she felt honoured in sharing the prison of the mother of her old school friend. In short, that evening she was in a position to betray the Marquise's confidence to Licquet. She had learned that Mme. Acquet had assisted at many of the attacks on coaches, dressed as a man. Mme. de Combray dreaded nothing more than to have her daughter fall into the hands of the police. "If she is taken," she said, "she will accuse me." The Marquise was resigned to her fate; she knew she was destined for the scaffold; "after all, the King and the Queen had perished on the guillotine, and she would die there also." However, she was anxious to know if she could be saved by paying a large sum; but not a word was said about the yellow horse.