"Oh, well, Mr. Hetherwick, I don't suppose they're in any personal danger," answered Matherfield. "They're in the hands of brigands, no doubt, but I don't think there'll be any maltreatment of them—set your mind at rest about that. They don't do that sort of thing nowadays; it's all done politely and with every consideration, I believe. As to where they are? Why, somewhere in London! And there are over seven millions of other people in London, and hundreds upon hundreds of thousands of inhabited houses—a lot of needles in that bundle of hay, gentlemen!"

"They've got to be found!" repeated Hetherwick doggedly. "You'll have to set all your machinery to work! This can't——"

"Wait a bit, Hetherwick," interrupted Penteney. He turned to Matherfield. "You said you had news of this man Ambrose? What news?"

Matherfield tapped the printed bill which lay on his desk.

"I had that circulated broadcast this morning," he answered. "And then, of course, the newspapers have helped. Well, not so very long before you came in, I was called to the telephone by a man named Killiner, who told me he was the landlord of the Green Archer Tavern, in Wood Street, Westminster——"

"Westminster again!" exclaimed Hetherwick. "That seems to be the centre point!"

"And a very good thing to have a centre-point, Mr. Hetherwick," said Matherfield. "When things begin to narrow down, one gets some chance. Well, I was saying—this man rang me up to say that if I'd go down there he thought he could give me some information relative to the bill about the missing man. What he'd got to say, he said, was too long for a telephone talk. I answered that I'd be with him shortly, and I was just setting off when you arrived. Of course, I don't know what he can tell—it may be nothing, it may be something. Perhaps you gentlemen would like to go with me and hear what it is?"

"I would, but I mustn't," replied Penteney. "I must go to my office and hear if Lady Riversreade or the local police have had any fresh news. Keep in touch with me, though, Matherfield—let me know what you hear."

"I'll go with you," said Hetherwick. "Westminster!" he muttered again, when Penteney had gone. "It looks as if this man Ambrose was known in that district."

"Likely!" assented Matherfield. "But you know, Mr. Hetherwick, there are some queer spots in that quarter! People who know the purely ornamental parts of Westminster, such as the Abbey, and the Houses of Parliament, and Victoria Street, and so on, don't know that there are some fine old slums behind 'em! But I'll show you when we get down there. We shall go through one or two savoury slices."