WHITTINGTON and his companion were walking at a good pace. Tommy started in pursuit at once, and was in time to see them turn the corner of the street. His vigorous strides soon enabled him to gain upon them, and by the time he, in his turn, reached the corner the distance between them was sensibly lessened. The small Mayfair streets were comparatively deserted, and he judged it wise to content himself with keeping them in sight.

The sport was a new one to him. Though familiar with the technicalities from a course of novel reading, he had never before attempted to "follow" anyone, and it appeared to him at once that, in actual practice, the proceeding was fraught with difficulties. Supposing, for instance, that they should suddenly hail a taxi? In books, you simply leapt into another, promised the driver a sovereign—or its modern equivalent—and there you were. In actual fact, Tommy foresaw that it was extremely likely there would be no second taxi. Therefore he would have to run. What happened in actual fact to a young man who ran incessantly and persistently through the London streets? In a main road he might hope to create the illusion that he was merely running for a bus. But in these obscure aristocratic byways he could not but feel that an officious policeman might stop him to explain matters.

At this juncture in his thoughts a taxi with flag erect turned the corner of the street ahead. Tommy held his breath. Would they hail it?

He drew a sigh of relief as they allowed it to pass unchallenged. Their course was a zigzag one designed to bring them as quickly as possible to Oxford Street. When at length they turned into it, proceeding in an easterly direction, Tommy slightly increased his pace. Little by little he gained upon them. On the crowded pavement there was little chance of his attracting their notice, and he was anxious if possible to catch a word or two of their conversation. In this he was completely foiled; they spoke low and the din of the traffic drowned their voices effectually.

Just before the Bond Street Tube station they crossed the road, Tommy, unperceived, faithfully at their heels, and entered the big Lyons'. There they went up to the first floor, and sat at a small table in the window. It was late, and the place was thinning out. Tommy took a seat at the table next to them, sitting directly behind Whittington in case of recognition. On the other hand, he had a full view of the second man and studied him attentively. He was fair, with a weak, unpleasant face, and Tommy put him down as being either a Russian or a Pole. He was probably about fifty years of age, his shoulders cringed a little as he talked, and his eyes, small and crafty, shifted unceasingly.

Having already lunched heartily, Tommy contented himself with ordering a Welsh rarebit and a cup of coffee. Whittington ordered a substantial lunch for himself and his companion; then, as the waitress withdrew, he moved his chair a little closer to the table and began to talk earnestly in a low voice. The other man joined in. Listen as he would, Tommy could only catch a word here and there; but the gist of it seemed to be some directions or orders which the big man was impressing on his companion, and with which the latter seemed from time to time to disagree. Whittington addressed the other as Boris.

Tommy caught the word "Ireland" several times, also "propaganda," but of Jane Finn there was no mention. Suddenly, in a lull in the clatter of the room, he got one phrase entire. Whittington was speaking. "Ah, but you don't know Flossie. She's a marvel. An archbishop would swear she was his own mother. She gets the voice right every time, and that's really the principal thing."

Tommy did not hear Boris's reply, but in response to it Whittington said something that sounded like: "Of course—only in an emergency...."

Then he lost the thread again. But presently the phrases became distinct again whether because the other two had insensibly raised their voices, or because Tommy's ears were getting more attuned, he could not tell. But two words certainly had a most stimulating effect upon the listener. They were uttered by Boris and they were: "Mr. Brown."

Whittington seemed to remonstrate with him, but he merely laughed.

"Why not, my friend? It is a name most respectable—most common. Did he not choose it for that reason? Ah, I should like to meet him—Mr. Brown."

There was a steely ring in Whittington's voice as he replied:

"Who knows? You may have met him already."

"Bah!" retorted the other. "That is children's talk—a fable for the police. Do you know what I say to myself sometimes? That he is a fable invented by the Inner Ring, a bogy to frighten us with. It might be so."

"And it might not."

"I wonder ... or is it indeed true that he is with us and amongst us, unknown to all but a chosen few? If so, he keeps his secret well. And the idea is a good one, yes. We never know. We look at each other— one of us is Mr. Brown—which? He commands—but also he serves. Among us—in the midst of us. And no one knows which he is...."

With an effort the Russian shook off the vagary of his fancy. He looked at his watch.

"Yes," said Whittington. "We might as well go."

He called the waitress and asked for his bill. Tommy did likewise, and a few moments later was following the two men down the stairs.

Outside, Whittington hailed a taxi, and directed the driver to go to Waterloo.

Taxis were plentiful here, and before Whittington's had driven off another was drawing up to the curb in obedience to Tommy's peremptory hand.

"Follow that other taxi," directed the young man. "Don't lose it."

The elderly chauffeur showed no interest. He merely grunted and jerked down his flag. The drive was uneventful. Tommy's taxi came to rest at the departure platform just after Whittington's. Tommy was behind him at the booking-office. He took a first-class single ticket to Bournemouth, Tommy did the same. As he emerged, Boris remarked, glancing up at the clock: "You are early. You have nearly half an hour."

Boris's words had aroused a new train of thought in Tommy's mind. Clearly Whittington was making the journey alone, while the other remained in London. Therefore he was left with a choice as to which he would follow. Obviously, he could not follow both of them unless—— Like Boris, he glanced up at the clock, and then to the announcement board of the trains. The Bournemouth train left at 3.30. It was now ten past. Whittington and Boris were walking up and down by the bookstall. He gave one doubtful look at them, then hurried into an adjacent telephone box. He dared not waste time in trying to get hold of Tuppence. In all probability she was still in the neighbourhood of South Audley Mansions. But there remained another ally. He rang up the Ritz and asked for Julius Hersheimmer. There was a click and a buzz. Oh, if only the young American was in his room! There was another click, and then "Hello" in unmistakable accents came over the wire.

"That you, Hersheimmer? Beresford speaking. I'm at Waterloo. I've followed Whittington and another man here. No time to explain. Whittington's off to Bournemouth by the 3.30. Can you get there by then?"

The reply was reassuring.

"Sure. I'll hustle."

The telephone rang off. Tommy put back the receiver with a sigh of relief. His opinion of Julius's power of hustling was high. He felt instinctively that the American would arrive in time.

Whittington and Boris were still where he had left them. If Boris remained to see his friend off, all was well. Then Tommy fingered his pocket thoughtfully. In spite of the carte blanche assured to him, he had not yet acquired the habit of going about with any considerable sum of money on him. The taking of the first-class ticket to Bournemouth had left him with only a few shillings in his pocket. It was to be hoped that Julius would arrive better provided.

In the meantime, the minutes were creeping by: 3.15, 3.20, 3.25, 3.27. Supposing Julius did not get there in time. 3.29.... Doors were banging. Tommy felt cold waves of despair pass over him. Then a hand fell on his shoulder.

"Here I am, son. Your British traffic beats description! Put me wise to the crooks right away."

"That's Whittington—there, getting in now, that big dark man. The other is the foreign chap he's talking to."

"I'm on to them. Which of the two is my bird?"

Tommy had thought out this question.

"Got any money with you?"

Julius shook his head, and Tommy's face fell.

"I guess I haven't more than three or four hundred dollars with me at the moment," explained the American.

Tommy gave a faint whoop of relief.

"Oh, Lord, you millionaires! You don't talk the same language! Climb aboard the lugger. Here's your ticket. Whittington's your man."

"Me for Whittington!" said Julius darkly. The train was just starting as he swung himself aboard. "So long, Tommy." The train slid out of the station.

Tommy drew a deep breath. The man Boris was coming along the platform towards him. Tommy allowed him to pass and then took up the chase once more.

From Waterloo Boris took the tube as far as Piccadilly Circus. Then he walked up Shaftesbury Avenue, finally turning off into the maze of mean streets round Soho. Tommy followed him at a judicious distance.

They reached at length a small dilapidated square. The houses there had a sinister air in the midst of their dirt and decay. Boris looked round, and Tommy drew back into the shelter of a friendly porch. The place was almost deserted. It was a cul-de-sac, and consequently no traffic passed that way. The stealthy way the other had looked round stimulated Tommy's imagination. From the shelter of the doorway he watched him go up the steps of a particularly evil-looking house and rap sharply, with a peculiar rhythm, on the door. It was opened promptly, he said a word or two to the doorkeeper, then passed inside. The door was shut to again.

It was at this juncture that Tommy lost his head. What he ought to have done, what any sane man would have done, was to remain patiently where he was and wait for his man to come out again. What he did do was entirely foreign to the sober common sense which was, as a rule, his leading characteristic. Something, as he expressed it, seemed to snap in his brain. Without a moment's pause for reflection he, too, went up the steps, and reproduced as far as he was able the peculiar knock.

The door swung open with the same promptness as before. A villainous-faced man with close-cropped hair stood in the doorway.

"Well?" he grunted.

It was at that moment that the full realization of his folly began to come home to Tommy. But he dared not hesitate. He seized at the first words that came into his mind.

"Mr. Brown?" he said.

To his surprise the man stood aside.

"Upstairs," he said, jerking his thumb over his shoulder, "second door on your left."