Gurdon looked out from the shelter of the great portico to see the sheets of rain falling on the pavement. Silence reigned supreme but for the steady plash of the raindrops as they rattled on the pavements. To walk half a mile on such a night meant getting wet through; and Gurdon somewhat ruefully regarded his thin slippers and his light dust overcoat. Half a dozen times the night porter blew his whistle, but no sign of a cab could be seen.

"We shan't get one to-night," Venner said. "They are all engaged. There is only one thing for it—you must take a room here, and stay till the morning. I've no doubt I can fit you up in the way of pyjamas and the things necessary."

Gurdon fell in readily enough with the suggestion. Indeed, there was nothing else for it. He took his number and key from the sleepy clerk in the office, and made his way upstairs to Venner's bedroom.

"I'll just have one cigarette before I turn in," he said. "It seems as if Fate had ordained that I am to keep in close touch with the leading characters of the mystery. By the way, we never took the trouble to find out who the handsome cripple was."

"That is very easily done in the morning," Venner replied. "A striking personality like that is not soon lost sight of. Besides, he has doubtless been here before, for, if you will recollect, his attendants took him to the right table as if it had been ordered beforehand. And now, if you don't mind, I'll turn in—not that I expect to sleep much after an exciting evening like this. Good night, old fellow."

Gurdon went on to his own room, where he slowly undressed and sat thinking the whole thing out on the edge of his bed. Perhaps he was suffering from the same suppressed excitement which at that moment was keeping Venner awake, for he felt not the slightest disposition to turn in. Usually he was a sound sleeper; but this night seemed likely to prove an exception to the rule.

An hour passed, and Gurdon was still sitting there, asking himself whether it would not be better to go to bed and compel sleep to come to him. Impatiently he turned out his light and laid his head resolutely on the pillow.

But it was all in vain—sleep was out of the question. The room was not altogether in darkness, either; for the sleeping apartments on that landing had been arranged back to back with a large, open ventilator between them. Through this ventilator came a stream of light; evidently the occupant of the adjoining room had not yet retired. The light worried Gurdon; he asked himself irritably why his neighbor should be permitted to annoy him in this way. A moment or two later the sound of suppressed voices came through the ventilator, followed by the noise of a heavy fall.

At any ordinary time Gurdon would have thought nothing of this, but his imagination was aflame now, and his mind was full of hidden mysteries. It seemed to him that something sinister and underhand was going on in the next room.

Usually, no one would identify the Grand Empire Hotel with crime and intrigue; but that did not deter Gurdon from rising from his bed and making a determined effort to see through the ventilator into the adjoining room. It was not an easy matter, but by dint of balancing two chairs one on top of the other the thing was accomplished. Very cautiously Gurdon pushed back the glass slide and looked through. So far as he could see, there was nothing to justify any suspicion. The room was absolutely empty, though it was brilliantly lighted; and for a moment Gurdon felt ashamed of his suspicions, and turned away, half determined to try and sleep. It was at that instant that he noticed something out of the common. To his quickened ear there came a sound unmistakably like a snore, and pushing his body half through the ventilator he managed to make out the bed in the next room. On it lay the body of a boy in uniform, unmistakably a messenger boy or hotel attendant of that kind. Gurdon could see the hotel name embroidered in gold letters on his collar.

Perhaps there was nothing so very suspicious in this, except that the boy was lying on the bed fully dressed, even to his boots. It was a luxurious room; not at all the class of apartment to which the hotel management would relegate one of their messenger boys, nor was it possible that the lad had had the temerity to go into the vacant room and sleep.

"Something wrong here," Gurdon muttered. "Hang me if I don't get through the ventilator and see what it is."

It was no difficult matter for an athlete like Gurdon to push his way through and drop on to the bed on the other side. Then he shook the form of the slumbering lad without reward. The boy seemed to be plunged in a sleep almost like death. As Gurdon turned him over, he noticed on the other side of the lad's collar the single word "Lift." It began to dawn upon Gurdon exactly what had happened. In large hotels like the Grand Empire there is no fixed period when the lift is suspended, and consequently, it has its attendants night and day. For some reason, this boy had evidently been drugged and carried into the room where he now lay. There was no doubt whatever about it, for it was impossible to shake the lad into the slightest semblance of life. Gurdon crossed to the door, and found, not to his surprise, that it was locked. His first impulse was to return to his room and call the night porter; but a strange, wild idea had come into his mind, and he refrained from doing so. It occurred to him that perhaps Mark Fenwick or the cripple had had a hand in this outrage.

"I'll wait a bit," Gurdon told himself. "It is just possible that my key will fit this door. Anyway, it is worth trying."

Gurdon made his way back to his own room again, to return a minute or two later with his key. To his great delight the door opened, and he stood in a further corridor, close against the cage in which the lift worked noiselessly up and down.

It was absolutely quiet, so that anybody standing there would have been able to carry out any operation of an unlawful kind without observation. Gurdon stood, looking down the lift shaft, until he saw that the cage was once more beginning to ascend. It came up slowly and smoothly and without the least noise, until it was level with the floor on which Gurdon was standing. It was one of the open kind, so he could see inside quite clearly. To all practical purposes, the lift was empty, save for the presence of one man, who lay unconscious on the floor. The cage was ascending so leisurely that Gurdon was in a position to make a close examination of the figure before the whole structure had risen to the next floor. It did not need a second glance to tell Gurdon that the man in the cage was the attendant, and that he was suffering from the same drug which had placed his boy assistant beyond all power of interfering.

"Now what does all this mean?" Gurdon muttered. "Who is there on the floor above who is interested in getting these two people out of the way? What do they want to bring up or send down which it is not safe to dispose of by the ordinary means? I think I'll wait and see. No sleep for me to-night."

The lift vanished in the same silent way. It hung overhead for some little time, and once more appeared in sight, this time absolutely empty, save for a small square box with iron bands at the corners, which lay upon the floor. As the cage descended, Gurdon suddenly made up his mind what to do. He sprang lightly on to the top of the falling cage, and grasped the rope with both hands. A moment later and he was descending in the darkness.

As far as he could judge, the lift went down to the basement, where, for the time being, it remained. There was a warm damp smell in the air, suggestive of fungus, whereby Gurdon judged that he must be in the vaults beneath the hotel. As his eyes became accustomed to the gloom, he could make out just in front of him a circular patch of light, which evidently was a coal shoot.

He had no need to wait now for the full development of the adventure. He could hear whispered voices and the clang of metal, as if somebody had opened the door of the lift. One of the voices he failed to understand, but with a thrill he recognised the fact that the speaker was talking in either Spanish or Portuguese. Instantly it flashed into his mind that this was the language most familiar to the man who called himself Mark Fenwick. Beyond doubt he was quite right when he identified this last development with the actors in the dramatic events earlier in the evening.

"Now don't be long about it," a hoarse voice whispered. "There are two more cases to send up, and two more to come down here. Has that van come along, or shall we have to wait until morning?"

"The van is there right enough," another hoarse voice said. "We have the stuff out on the pavement. Let's have the last lot here, and get it up at once."

Gurdon could hear the sound of labored breathing as if the unseen man was struggling with some heavy burden. Presently some square object was deposited on the floor of the lift. It seemed to slip from someone's hands, and dropped with a heavy thud that caused the lift to vibrate like a thing of life."

"Clumsy fool," a voice muttered. "You might have dropped that on my foot.
What did you want to let go for?"

"I couldn't help it," another voice grumbled. "I didn't know it was half so heavy. Besides, the rope broke."

"Oh, are you going to be there all night?"—another voice, with a suggestion of a foreign accent in it, asked impatiently. "Don't forget you have to bring the man down yet, and see that the boy is taken to his place. Now, up with it."

Standing there, holding on to the rope and quivering with excitement, Gurdon wondered what was going to happen next. Once more he felt himself rising, and an instant later he was in the light again. He waited till the lift had reached his own floor; then he jumped quickly down, taking care as he went to note the heavy box which lay on the floor of the lift. A corner of it had been split open by the heavy jar, and some shining material like sand lay in a little heap, glittering in the rays of the electric light.

Gurdon stood there panting for a moment, and rather at a loss to know what to do next. Once more the lift came down, this time with two boxes of a smaller size. They vanished; and as the lift rose once again, Gurdon had barely time to hide himself behind the bedroom door, and thus escape the observation of two men who now occupied the cage. He just caught a fleeting glimpse of them, and saw that one was an absolute stranger, but he felt his heart beating slightly faster as he recognised in the other the now familiar form of Mark Fenwick. The mystery was beginning to unfold itself.

"That was a close thing," Gurdon muttered, as he wiped his hot face. "I think I had better go back to my own room, and wait developments. One can't be too careful."

The lift-boy was still sleeping on the bed; but his features were twitching, as if already the drug was beginning to lose its effect. At least, so Gurdon shrewdly thought, and subsequent events proved that he was not far wrong. He was standing in his own room now, waiting by the ventilator, when he heard the sound of footsteps on the other side of the wall. Two men had entered the room, and by taking a little risk, Gurdon could see that they were examining the unconscious boy coolly and critically.

"I should think about five minutes more would do it," one of them said. "Better carry him out, and shove him in that little sentry box of his. When he comes to himself again he won't know but what he has fallen asleep; barring a headache, the little beggar won't be any the worse for the adventure."

"Have we got all the stuff up now?" the other man asked.

"Every bit of it," was the whispered reply. "I hope the old man is satisfied now. It was not a bad idea of his to work this little game in a great hotel of this kind. But, all the same, it is not without risks, and I for one should be glad to get away to that place in the country where we are going in a week or two."

Gurdon heard no more. He allowed the best part of half-an-hour to pass before he ventured once more to creep through the ventilator and reach the landing in the neighborhood of the lift. Everything looked quite normal now, and as if nothing had happened. The lift boy sat in his little hut, yawning and stretching himself. It was quite evident that he knew nothing of the vile uses he had been put to. A sudden idea occurred to Gurdon.

"I want you to bring the lift up to this floor," he said to the boy. "No, I don't want to use it; I have lost something, and it occurs to me that I might have left it in the lift."

In the usual unconcerned manner of his class the boy touched an electric button, and the lift slowly rose from the basement.

"Does this go right down to the cellars?" Gurdon asked.

"It can if it's wanted to," the boy replied. "Only it very seldom does. You see, we only use this lift for our customers. It's fitted with what they call a pneumatic cushion—I mean, if anything goes wrong, the lift falls into a funnel shaped well, made of concrete, which forms a cushion of air, and so breaks the fall. They say you could cut the rope and let it down without so much as upsetting a glass of water. Not that I should like to try it, sir, but there you are."

Gurdon entered the lift, where he pretended to be searching for something for a moment or two. In reality, he was scraping up some of the yellow sand which had fallen from the box to the floor of the lift, and this he proceeded to place in a scrap of paper. Then he decided that it was absolutely necessary to retire to bed, though he was still in full possession of his waking faculties. As a matter of fact, he was asleep almost as soon as his head touched the pillow. Nevertheless, he was up early the following morning, and in Venner's bedroom long before breakfast. He had an exciting story to tell, and he could not complain that in Venner he had anything but an interested listener.

"We are getting on," the latter said grimly. "But before you say anything more, I should like to have a look at that yellow sand you speak of. Bring it over near the light."

Venner let the yellow stuff trickle through his hands; then he turned to
Gurdon with a smile.

"You look upon this as refuse, I suppose?" he said. "You seem to imagine that it is of no great value."

"Well, is it?" Gurdon asked. "What is it?"

"Gold," Venner said curtly. "Pure virgin gold, of the very finest quality. I never saw a better sample."