He was exercising his brains over a possible solution of this problem when Fullaway suddenly appeared in the hall behind him, accompanied by a man whom Allerdyke at once took to be the very individual about whom he was speculating. He was a man of apparently forty years of age, of average height and build, of a full countenance, sallow in complexion, clean-shaven, wearing gold-rimmed spectacles over a pair of sapphire blue eyes--a shrewd, able-looking man, clad in the loose fitting, square-cut garments just then affected by his fellow-countrymen, and having a low-crowned, soft straw hat pulled down over his forehead. His hands were thrust into the pockets of his jacket; a long, thin, black cigar stuck out of a corner of his humorous-looking lips; he cocked an intelligent eye at Allerdyke as he and Fullaway advanced to the door. "Hullo, Allerdyke!" said Fullaway in his usual vivacious fashion. "Viewing the prospect o'er, eh? Allow me to introduce Mr. Van Koon, whom I don't think you've met, though he's under the same roof. Van Koon, this is the Mr. Allerdyke I've mentioned to you." The two men shook hands and stared at each other. Whoever and whatever this man may be, thought Allerdyke, he gives you a straight look and a good grip--two characteristics which in his opinion went far to establish any unknown individual's honesty. "No," remarked Van Koon. "I haven't had the pleasure of meeting Mr. Allerdyke before. But I'm out a great deal--I don't spend much time indoors this fine weather. You gentlemen know your London well--I don't, and I'm putting in all the time I can to cultivate her acquaintance." "Been in town long?" asked Allerdyke, wanting to say something and impelled to this apparently trite question by the New Yorker's own observations. "Since the first week in April," answered Van Koon, "And as this is my first visit to England, I'm endeavouring to do everything well. Fullaway tells me, Mr. Allerdyke, that you come from Bradford, the big manufacturing city up north. Well, now, Bradford is one of the places on my list--hullo!" he exclaimed, breaking off short. "I guess here's a man who's wanting you, Fullaway, in a considerable bit of a hurry." Fullaway and Allerdyke looked out on to the pavement and saw Blindway, who had just jumped out of a taxi-cab, and was advancing upon them. He came up and addressed them jointly--would they go back with him at once to New Scotland Yard?--the chief wanted to see them for a few minutes. "Come on, Allerdyke," said Fullaway. "We'd better go at once. Van Koon," he continued, turning to his compatriot, "do me a favour--just look in at my rooms upstairs, and tell Mrs. Marlow, if she's come--she hadn't arrived when I was up there ten minutes ago--that I'm called out for an hour or so--ask her to attend to anything that turns up until I come back--shan't be long." Van Koon nodded and walked back into the hotel, while Allerdyke and Fullaway joined the detective in the cab and set out westward.