Nancy welcomed him with an encouraging smile. "We have met before, Mr. Bates," she said. "I don't suppose you remember, but it was one night in Whitcomb Street, when I was in the car with Doctor Ashton." Joe grinned a trifle nervously. "That's right, miss," he observed. "I ain't forgot yer--not me." He pulled off his cap and scratched the back of his closely cropped head. "I got a bit o' noos for the doctor," he continued. "D'you happen to know when 'e's likely to be in, miss?" "That's the very point we were talking about," replied Nancy. "He went out at half-past five and he left a message that he would be back by six at the latest." Joe stared at her. "Well, that's a bit queer," he remarked. "'E ain't the sort to say a thing and then not do it." "It's queerer than it looks," was Nancy's answer. "Six o'clock is the time at which he sees his outdoor patients. He wouldn't forget that, however busy he was." "Did 'e tell yer where 'e was goin' to?" "He told me," broke in Martha Jane. "Some 'ouse down at the bottom of Flood Lane." A swift change manifested itself in Joe's face. "Flood Lane!" he almost shouted. "You're sure 'e said Flood Lane?" "Of course I am. I ain't deaf, Mr. Bates." Joe took no notice of the snub. "Wot made 'im go there?" he demanded. "'E was fetched," replied Martha Jane with some asperity. "Fetched by a party who hadn't no better manners----" "'Ere," interrupted Joe, "wot was the bloke like? You answer me quick." Martha Jane flushed indignantly, but before her lips could frame a protest she was forestalled by Nancy. "It's all right, Martha. Mr. Bates is afraid that something may have happened to Doctor Gray, and he wants to help us. That's so, isn't it?" She turned quickly to Joe, who nodded his head. "Well," replied Martha Jane, in a slightly mollified voice, "'e was just a rough common-looking man the same as you can see 'anging about the street corners I'd know 'im anywhere, though, if only by the scar on 'is face." There was a half-stifled oath from Joe. "Jake 'Udson!" he cried. "Jake 'Udson it was for a million!" He clenched his fists and glared savagely at the two women. "Nah ye can see why he ain't come back." Nancy's heart was beating swiftly, but to all outward appearance she remained perfectly cool. "Don't waste time," she said. "Tell me what you mean at once. I know that you're a friend of Doctor Gray's, and I know that he asked you to follow a man outside the station." Joe moistened his lips. "That's it, miss. A bloke of the name o' 'Spike' Cooper. 'E's 'and an' glove with this 'ere Jake 'Udson, an' there ain't two dirtier blackguards, not in the 'ole o' London." Nancy's face had gone very white. "Do you know this place--Flood Lane?" she demanded.