Melky, who had grown breathless in his efforts to carry out his companion's wishes, turned and looked at him with no attempt to conceal his wonder.

"Well, s'elp me if you ain't a cool 'un, Mr. Ayscough!" he exclaimed. "Here you troubles to track a chap to this here Underground Railway, seen him pop into it like a rabbit into a hole—and let's him go! What did we follow him up Gower Street for? Just to see him set off for a ride?"

"All right, my lad!" repeated Ayscough. "You don't quite understand our little ways. Wait here a minute."

He drew one of his cards from his pocket and carrying it into the booking office exchanged a few words with the clerk at the window. Presently he rejoined Melky. "He took a ticket for Whitechapel," remarked Ayscough as he strolled quietly up. "Ah! now what does a young Japanese medical student want going down that way at eleven o'clock at night? Something special, no doubt, Mr. Rubinstein. However, I'm going westward just now. Just going to have a look in at the Great Western Hotel, to see if Mr. Purdie heard anything from that American chap—and then I'm for home and bed. Like to come to the hotel with me?"

"Strikes me we might as well make a night of it!" remarked Melky as they recrossed the road and sought a west-bound train. "We've had such an evening as I never expected! Mr. Ayscough! when on earth is this going to come to something like a clearing-up?"

Ayscough settled himself in a corner of a smoking-carriage and leaned back.

"My own opinion," he said, "is that it's coming to an end. Tomorrow, the news of the Chinaman's murder'll be the talk of the town. And if that doesn't fetch Levendale out of whatever cranny he's crept into, hanged if I know what will!"

"Ah! you think that, do you?" said Melky. "But—why should that news fetch him out?"

"Don't know!" replied Ayscough, almost unconcernedly. "But I'm almost certain that it will. You see—I think Levendale's looking for Chen Li. Now, if Levendale hears that Chen Li's lying dead in our mortuary—what? See?"

Melky murmured that Mr. Ayscough was a cute 'un, and relapsed into thought until the train pulled up at Praed Street. He followed the detective up the streets and across the road to the hotel, dumbly wondering how many times that day he had been in and about that quarter on this apparently interminable chase. He was getting dazed—but Ayscough who was still smoking the cigar which Yada had given him, strode along into the hotel entrance apparently as fresh as paint.