You will now relate to me, as accurately as you can,” said Carpentaria somewhat peremptorily to Pratt the chauffeur, “exactly what were the circumstances which led to your ceasing to be master of your car.”

Carpentaria had had Pratt and the Soudanese carried to the strong-room, the heart of the City, where a chemist and Dr. Rivers had united to treat them for the effects of the narcotic which had evidently, by some means, been administered to them. Rivers repeated that, so far as he could judge, the narcotic employed was chloral hydrate, a drug more powerful than morphine, more effective in its action on the heart, and less annoying to other functional parts of the body. When Rivers and the chemist had finished their ministrations, Carpentaria had politely intimated to them that he did not absolutely insist on their remaining—a piece of information which surprised the doctor, who, having been let into one of his director’s secrets, expected, with the confidence of youth, to be let into all of them. The three men, two white and one Ethiop, were thus alone together in the chamber.

“Well, sir,” said Pratt, who was a fair man, talkative, with, just at present, a terrific sense of his own importance as the central hero of a mysterious drama. “It was like this: After I’d had the drink——”

“What drink?” demanded Carpentaria sharply. “The drink the other driver offered to me, sir.”

“What other driver?”

“There came up another driver, sir.”

“In the City uniform?”

“Yes, sir.”

“Who was he? What was his name?”

“No idea, sir. I seemed to remember his face, like, but I couldn’t recollect his name. I asked him his name, and he said: ‘Don’t try to be funny, Pratt; you’ve had a drop too much.’”

“And had you?”

“Not I, sir—of course I hadn’t. I’d made two journeys to the Bank with full loads, and the next one was to be the last, and——”

“And you hadn’t had anything to drink at all?”

“Nothing to speak of, sir. A glass of port at Short’s as I was coming back the first time, and a pint of beer—or it might have been a pint and a half—at the Redcliffe as I was coming back the second time.”

“That was absolutely all?”

“Yes, sir, except a drop of whisky which was left in my flask.”

“But how came the other driver to be in a position to offer you drink? Was he carrying casks and other things about with him?”

“No, sir, only a flask. Every chauffeur has a flask. Necessary, sir. Cold work, sir. And you’ll recollect it hasn’t been exactly sultry to-night.”

“What did he say? Are you in the habit of accepting drinks from men whose names you can’t call to mind?”

“He was in the profession, sir, and in the uniform; besides, he said he’d got a new cordial, fresh from Madeira, that would keep anyone warm, even in the depth of winter, for at least two hours.”

“But this isn’t the depth of winter.”

“No, sir; but, as the cordial was handy, I thought I might as well try it.”

“And when you had tried it?”

“I felt rather jolly, sir. I never felt better in my life, and thinks I to myself: ‘I’d better write down the name and address of this cordial before I forget it.’ So I says: ‘What’s-your-name,’ I says, meaning the other driver, ‘what’s the name and address of this cordial, before I forget it?’ And I was just taking a pencil out of my pocket to write it down when I felt a bit less jolly and the pencil wouldn’t stop in my hand.”

“You were on your driving seat?”

“Yes, sir.”

“And that is all you remember?”

“Yes, sir. Except that once, dreamy like, I thought I was in prison for exceeding the legal limit, and that all the lights in the prison were turned out, and an earthquake was going on.”

“The other driver stood in the road by the car, eh?”

“Yes, sir.”

“How was he dressed?”

“I’ve told you, sir. This uniform. Blue and white cap, same as this, and long overcoat.”

“You couldn’t see what he wore underneath the overcoat?”

“No, sir.”

“And you?” Carpentaria turned swiftly on the Soudanese. “Did you drink too?”

“Yes, sah.”

Spats smiled.

“And after you had drunk?”

Spats shook his head, still smiling.

“You remember nothing?”

“Yes, sah.”

“What?”

“He means he doesn’t remember anything,” Pratt explained.

“You mean you remember nothing?” Carpentaria questioned.

“Yes, sah.”

“Why did you drink?”

“Yes, sah.”

The Soudanese looked at Pratt, smiling.. “Because Pratt drank?”

“Yes, sah.”

“You have been waiting on Mr. Ilam lately, haven’t you?”

“Yes, sah.”

“When he came to the outer door there, and entered in here, did he tell you to wait outside?”

“Yes, sah.”

“You can both go,” said Carpentaria. “Come to me at eight o’clock to-morrow, Pratt, in case I should want you.”

“Yes, sir,” said Pratt. “Yes, sah,” said the Soudanese.

“No, not you,” Carpentaria explained.

“Yes, sah.”

“One moment,” said Carpentaria to the Ethiopian. “Did Mr. Ilam or any other person give you a note to hand to the doorkeeper outside there?” The Soudanese shook his fierce and yet amiable head.

“What!” cried Pratt, addressing him in surprise, “didn’t you come up and give a note to Wiggins and then go away again, and return a second time?” The Soudanese shook his head once more.

“Then there must have been two of ’em, sir,” said Pratt to Carpentaria. “This chap’s honest enough.”

“Me have brother,” said the Soudanese, “same me.”

“Where is your brother?”

The Soudanese shook his head.

“In the native village?”

“Yes, sah.”

“Go and fetch him,” ordered Carpentaria.

And the next moment he was alone in the great chamber, and he felt tempted simply to go to the regular police, of whom a few were constantly employed by the City, and tell them what had happened, and leave the whole affair entirely in their hands. And then the strange attraction which always emanates from a mystery appealed to him so strongly that he determined to probe a little further into the peculiar matter of Ilam’s disappearance, without the aid of professional detectives. He didn’t imagine for an instant that Ilam was dead. He was capable of believing that Ilam had disappeared willingly; and yet such a theory, having regard to the recitals of Mr. Gloucester and of the bank-clerk (by this time doubtless on his way to Weybridge, and the young thing) was to say the least exceedingly improbable.

He unlocked the door and went outside. Wiggins was at his post, actuated by the exaggerated alertness which characterizes one who has been caught napping.

“Anything happened, Wiggins?”

“No, sir. Nothing whatever.”

“I shall return soon. If the Soudanese comes, keep him.”

“Yes, sir.”

He passed into the Central Way, which was almost deserted. The last visitor, the very last stalwart of the Y.M.C.A., had departed, and the sole signs of life in the great thoroughfare were a lamplighter extinguishing the gas-lamps which were provided in case of a sudden failure of electricity, and a road-sweeper in charge of a complicated machine with two horses. The clock in the tower of the Exposition Palace showed half an hour after closing time. The moon was peeping over the eastern roofs.

Carpentaria went to the garage, and, not without difficulty, for it was shut up, made his way into the interior and procured some light. He wished to make a thorough examination of the car which had been employed as the instrument of the plot. He had it drawn out to the centre of the garage, under the full flare of an electric chandelier. A sleepy attendant hovered in the background.

“Get a ladder and see if there’s anything on the roof of the van—any tyres or boxes or anything,” said Carpentaria.

“There’s only this, sir,” replied the attendant when he had climbed up, and he produced a cap and overcoat of the City uniform.

“Well, I’m——!” exclaimed Carpentaria, and a notion struck him.

“Doorkeeper gone to bed?” he queried.

“Yes, sir.”

“Wake him and tell him I want him.”

While waiting for the doorkeeper, Carpentaria scrutinized attentively the wheels of the vehicle; those wheels, even on his first visit, had put an idea into his head. Then the doorkeeper arrived, not quite as spruce and perfect as a doorkeeper ought to be.

“No one can enter this garage except under your observation?” Carpentaria asked him.

“No one,” said the doorkeeper, positively.

“But you don’t keep such a careful eye on the people who go out?”

“Naturally not, sir. They can’t go out till they’ve been in, and if they’ve been in they’re all right.”

“Just so. Now try to remember. Soon after this car returned to the garage to-night, did any one leave the garage who was unfamiliar to you?”

“I don’t remember, sir. You see, sir——”

“Exactly. I see. I am not blaming you. Your theory, though defective, is a natural one. Now, do you remember, for instance, a man in a blue suit, with grey hair, going out?”

“Upon my soul, I believe I do, sir.”

“You are certain?”

“Oh, no, sir. I’m not certain. But I have a sort of a hazy idea——”

“Look at these wheels,” Carpentaria cut him short. “That’s clayey mud, isn’t it?”

“Yes, sir.”

“Where could the car have been to get that?”

“There’s that passage down under the embankment, sir, that way as leads to the river.”

“Doorkeeper,” said Carpentaria, “you are brilliant. I also have thought of that spot, where just such clay exists. But why should the car go down there?”

“Ah,” said the doorkeeper. “There you beat me, sir.”

“Then perhaps you are not so brilliant after all,” said Carpentaria.

And having minutely examined the interior of the car, with no result, he left the garage, and returned to the strong room.

The Soudanese was awaiting him at the door, and there were evident signs of a quarrelsome temper on the part of Wiggins. Wiggins had not forgotten the colour of the messenger who had handed him the forged note.

“Well?” Carpentaria asked of the Soudanese. “Where’s your brother?”

The man shook his head, but not smilingly.

“Has he gone?”

“Yes, sah.”

“No one knows at the village where he’s gone?”

Spats shook his head.

“Wiggins,” said Carpentaria. “Is this the man who brought you the note?”

Wiggins hesitated.

“No, sir,” he said at length’, resentfully. “But they’re all alike, them folk are.”

“H’m!” murmured Carpentaria. “Since there is nothing to guard here, you may as well go, Wiggins. You, too, Spats.”

Two minutes later he was crossing the Oriental Gardens in the direction of the Thames. And when he had travelled two hundred yards or so he heard footsteps behind him, light, rapid, irregular. He turned quickly, his hand on the revolver in his pocket, to face his pursuer. His pursuer, however, was Pauline Dartmouth and no other. So he left the revolver where it was.