She spent the rest of the morning, and most of the afternoon, searching the houses near the point on the road to Versailles indicated by Valentin. With her were three men from the Prefect's office—silent, able men, in plain clothes, who pretended to be keepers from the Jardin des Plantes, in search of a dangerous cobra, which was supposed to have escaped from its cage the night before.
The terrified householders threw open their doors with unassumed alacrity. The suggestion of a deadly reptile lurking in their gardens was a veritable open sesame. Yet no traces of the missing boy were found, and, more remarkable still, Grace was unable to identify any of the many gardens as the one in which she had seen the child playing with the spaniel. This disappointed her greatly. She knew well that, if Valentin was telling the truth, the garden was here; yet, although they visited every house within a quarter of a mile, they were unable to locate it. She remembered now that in her agitation, her eager examination of the child, she had not fixed upon her mind any salient point in the garden itself. All that she remembered was a bit of grass, a gravel walk, and the child playing with the dog. A dozen of the little enclosures presented similar features. She returned to the prefecture, baffled.
"The fellow is undoubtedly lying," had been Monsieur Lefevre's comment. "He is trying to throw you off the track, in order to protect the nurse, and possibly Mrs. Stapleton as well. I should not be surprised to find that the boy's mother is the guilty person."
Grace did not agree with him; so she said nothing. In spite of the fact that Mrs. Stapleton used cigarettes similar to those which seemed in some queer way to be at the bottom of the mystery, she had an intuitive feeling that the grief which the banker's wife showed was entirely real.
At half past seven, Grace left the prefecture in a high-powered car, furnished by Monsieur Lefevre. Alphonse Valentin was at the wheel. In her hand she held a pocket electric searchlight, across the front of which had been affixed a circular bit of blue glass.
At ten minutes to eight she arrived at Versailles. She at once ordered Valentin to turn and drive back toward Paris at moderate speed. She did not take him into her confidence regarding what she proposed to do, but kept a keen watch for the car containing Mr. Stapleton.
Her plan had worked. Mr. Stapleton, seeing her signal, had tossed her the package of money—she only hoped that the other part of her plan had been carried out with equal success.
The other part of the plan had been this: Monsieur Lefevre, who in build and general appearance was not unlike Mr. Stapleton, was to follow the latter's car in a machine of the same make and general appearance. He was to be driven by a chauffeur made up to resemble François sufficiently to be mistaken for him in the dim light of early evening. He himself was to make such alterations in his appearance and dress as would enable him to pass, under a cursory examination, for Stapleton. In the bottom of the car two armed men lay concealed.
When the car containing Mr. Stapleton turned back toward Paris, after having unwittingly delivered the money to Grace, the Prefect would continue on toward Versailles. He would know that the car containing the kidnappers was still ahead of him; since, had it not been, it, instead of Grace's car, would have signaled Mr. Stapleton.
Grace had started out from Versailles especially early, convinced that the kidnappers would not leave there until eight, at least. In this assumption she was correct. The car containing the kidnappers was, at that moment, creeping toward Paris some two miles in her rear, looking everywhere for Mr. Stapleton.