"Not the slightest," returned Mark. "I'm enjoying myself immensely. It's so dull down here as a rule that any little thing like a love affair or an attempted murder is a perfect godsend." He sauntered off to the surgery, and a few minutes later Colin, having scribbled a brief note to Nancy and left it on the hall table, was striding along the street in the direction of the Whitechapel Road. No one could describe the thoroughfares through which he had to pass as picturesque or engaging, but in the crisp morning air, and with a yellow sun shining down from overhead, the two-mile walk was not without a certain attraction. He was in the kind of mood, indeed, in which even the Dead Sea or the Sahara Desert would probably have appeared to possess some favourable features. Ever since he had discovered his real feelings toward Nancy the whole world seemed to have become an extraordinarily interesting and exciting place. At the present moment, both these sensations were intensified by the prospect of his approaching interview with Marsden. From the way in which the detective had spoken there could be little doubt that he had made some important discoveries, and the mere thought that in a few hours he might be helping to track down the Professor's murderer was sufficient in itself to set every nerve in Colin's body tingling with a fierce elation. Half-an-hour's walk brought him to the Palace, a gaudy structure wedged in between two public houses. The only person about who appeared to have any connection with the establishment was an elderly man with a bucket of paste, who was leisurely engaged in affixing a poster to one of the two boards which decorated each side of the entrance. Colin pulled up alongside of him. "Do you happen to know where Joe Bates lives?" he asked. The other paused in his work, and eyed him with some suspicion. "Yus," he replied, "an' wot abaht it?" "Nothing much," returned Colin. "I happen to be a pal of his, and I want to see him. My name's Doctor Gray." The elderly man's expression changed instantly. "Ow," he remarked, "that's orl right. I've 'eard 'im speak o' you. You're the bloke as mended 'im up when 'e was in 'orspital? Thinks the world o' you, Joe does, an' no error." "Well, in that case," said Colin, "perhaps you will trust me with his address?" "Why, o' course," was the answer. "No offence, mister, but I didn't know who you was when you come askin' fust. Might 'a' been one o' these 'ere blarsted rate collectors." He laid down his brush, and, stepping out on the pavement, pointed across toward a narrow turning on the opposite side of the road. "You foller that," he said, "an' when you come to the last 'ouse on the right jest give a couple o' taps on the front winder."