Unostentatiously he turned and strolled in the direction in which the dray was going, while he laboured to recall in its every detail the description he had read. A four-wheeled dray--that was right; a single horse--right also. A heavily made, iron-clamped cask with one stave broken at the end and roughly repaired by nailing. He glanced at the vehicle which had now drawn level with him. Yes, the cask was well and heavily made and iron clamped, but whether it had a broken stave he could not tell. The dray was painted a brilliant blue and had a Tottenham Court Road address. Here Constable Walker had a blow. This dray was a muddy brown colour and bore the name, John Lyons and Son, 127 Maddox Street, Lower Beechwood Road. He suffered a keen disappointment. He had been getting so sure, and yet---- It certainly looked very like what was wanted except for the colour. Constable Walker took another look at the reddish-brown paint. Curiously patchy it looked. Some parts were fresh and more or less glossy, others dull and drab. And then his excitement rose again to fever heat. He knew what that meant. As a boy he had had the run of the small painting establishment in the village in which he had been brought up, and he had learnt a thing or two about paint. He knew that if you want paint to dry very quickly you flat it--you use turpentine or some other flatting instead of oil. Paint so made will dry in an hour, but it will have a dull, flat surface instead of a glossy one. But if you paint over with flat colour a surface recently painted in oil it will not dry so quickly, and when it does it dries in patches, the dry parts being dull, the wetter ones glossy. It was clear to Constable Walker that the dray had been recently painted with flat brown, and that it was only partly dry. A thought struck him and he looked keenly at the mottled side. Yes, he was not mistaken. He could see dimly under the flat coat, faint traces of white lettering showing out lighter than the old blue ground. And then his heart leaped for he was sure! There was no possible chance of error! He let the vehicle draw ahead, keeping his eye carefully on it while he thought of his great luck. And then he recollected that there should have been four men with it. There was a tall man with a sandy moustache, prominent cheekbones, and a strong chin; a small, lightly made, foreign-looking man with a black beard and two others whose descriptions had not been given. The man with the beard was on the dray, but the tall, red-haired man was not to be seen. Presumably the driver was one of the undescribed men. It occurred to Constable Walker that perhaps the other two were walking. He therefore let the vehicle draw still farther ahead, and devoted himself to a careful examination of all the male foot-passengers going in the same direction. He crossed and recrossed the road. But nowhere could he see any one answering to the red-haired man’s description.