The servants had searched everywhere--in the house, in the grounds, and in the ruins, and later the police had gone over the same ground, and had searched everywhere on the estate; not a sign of the missing girl had been found. A footman, however, said he had heard a motor-car in the road about the time of the disappearance. He had listened, wondering who was coming to Whiteladies at that hour. The house stood in one corner of the estate, and there was a public road quite close to it, but it was a road little frequented. The marks of a car, which had stopped and turned at a point near the house, were plainly visible, and so far this was the only clue forthcoming. It proved an important one, because a tramp was found by the police who had seen a closed car traveling at a great speed toward the London road. The time, which he was able to fix very definitely, was about a quarter of an hour after Eva Wilkinson had gone on to the terrace. "Has the tramp been detained?" Quarles asked, and being answered in the negative, said he ought to have been. The professor examined the marks of the car minutely. There were two cars at Whiteladies, but neither of the tire markings were those of the car which had turned in the road. It is only natural, I suppose, that when a number of persons are brought in contact with a mystery their behavior should tend to become unnatural. It is one of a detective's chief difficulties to determine between innocent and suspicious actions, the latter being often the result of temperament or of a desire to emphasize innocence. I never found a decision more difficult than in the case of Eva Wilkinson's maid, a girl named Joan Perry; and because I could not decide in her case I was also suspicious of her young man Saunders, a gamekeeper on the estate. Joan Perry, a little later in the day, claimed to have made a remarkable discovery. A coat and skirt and a pair of walking shoes had been removed from her mistress's wardrobe. "What made you inspect her wardrobe?" I asked. The question seemed to confuse her, but she finally said it was because she wondered whether Miss Eva had gone away on purpose. According to Perry the affair with Edward Cayley was a serious one. To some extent her young mistress had confided in her, she declared. "Then she would hardly have gone away without letting you into the secret," I said. "That is what I cannot understand," she answered. Quarles agreed with me that this lent color to the idea that Eva Wilkinson had gone of her own accord. "It is possible--even probable," he said, "but if she did, I take it she has been deceived and walked into a trap. If we can find that car we shall be on the right road."