"Couldn't tell you that, guv'nor, d'yer see," said the lad, "'cause he's one o' them gents what allus wears a white silk handkercher abaht his face--up to his eyes. But he's a big man--wears black clothes." Viner gave the boy his promised reward, and was passing on when Miss Wickham touched his arm. "Ask if he's seen a lady go out this way," she said. "That's equally important." The boy, duly questioned nodded his head. "I see Mrs. Killerby go out not so long since," he answered. "Her what used to live here one time. Know her well enough." "Come along!" muttered Viner. "We've hit it! Mrs. Killerby--who is Mrs. Killenhall--used to live here at one time! Good--which means very bad, considering that without doubt the doctor who wears a white silk handkerchief about his face is the muffled man of Lonsdale Passage. Miss Wickham, something has alarmed these birds and they've flown." "But why were we brought here?" asked Miss Wickham. "I've an idea as to why you were," said Viner, "and I propose to find out at once if I'm right. Let's get away, find a taxicab, and go to your--but, good heavens!" he went on, breaking off as two men came into the yard. "Here's one of Carless' clerks, and Perkwite the barrister.--What are you doing here?" he demanded, as Millwaters and Perkwite hurried up. "Are you after anybody along there--in that house--the one at the end?" "We're after a good many things and people in Dr. Martincole's place, Mr. Viner," answered Millwaters. "Mr. Perkwite and I traced Mr. Cave here early in the afternoon; he went in, but he's never come out; we saw you enter--here you are. We saw Miss Wickham and Mrs. Killenhall--there's Miss Wickham, but where's the other lady? And where--" Viner stopped the clerk's questions with a glance, and he laughed a little as he gave him his answer. "My dear fellow," he said, "you should have posted somebody at the back here. Why, we don't quite know yet, but Miss Wickham and myself were trapped in there. As for Cave, he must be the man who went away with Martincole. As for Mrs. Killenhall, she too has gone. That boy down there saw all three go, some time ago, while we were locked up. But--what made you watch these people?" "We followed Cave," said Perkwite, "because Millwaters had been ordered to do so, and because I considered his conduct mysterious. Then, when we saw what was going on here,--your arrival following on that of Miss Wickham and Mrs. Killenhall,--we telephoned for Mr. Carless and more help. Carless and Lord Ellingham, and a couple of detectives, are at the front now. Millwaters and I heard from a denizen of these unlovely parts that there was a back entrance. We'd tried in vain for admittance at the front--" "But they've got in now, Mr. Perkwite!" exclaimed Millwaters suddenly. "See, there's Mr. Carless at a back window, waving to us to come in. I suppose we can get in by the back, Mr. Viner?"