Three days later, about four o'clock in the afternoon, Jack and Buck walked into Lincoln's Inn, and knocked at Mr. Buxton's door. They had been staying at a hotel near at hand, and nothing was said until Jack had carefully closed the door of the inner sitting-room, where Mr. Buxton was at work among his papers.

"So you're off to-morrow?" said Mr. Buxton, laying down his pen.

"No, to-night," said Jack.

"What?" returned Mr. Buxton in surprise. "Have you got all your luggage ready?"

"Yes, sir," said Buck. "We've got it with us."

"Oh, your cab is outside?" he said.

"No, sir," replied Buck, with a twinkle in his eye. "You see it all on view."

Mr. Buxton scratched his head. "Do you mean to say that you're going to start for Burmah with an umbrella apiece?"

"We do, Mr. Buxton," replied Jack. "We're going to slip off quietly. Buck thinks we're being watched."

"Watched!" cried Mr. Buxton. "By whom?"

"Can't say that," said Buck. "But there's someone takin' a deep interest in us I feel certain. I should venture to spec'late as the ruby gang want to know what we're up to."

"And you mean to start off for the other side of the world equipped merely for a stroll through the Park?" cried Mr. Buxton.

"Why not, sir?" asked Buck. "You've found us plenty of money, and we can rig ourselves out whereever there are shops. Best for us, too, to pull out on this business with as little show as we can make. If we don't, we may find ourselves pulled up mighty soon and mighty sharp. I tell you this is a deep an' cunning gang we've got to fight. An' they've got a big pull of us. They know us and we know very little of them. I can tell you there are wily birds east of Suez. They are up to all the tricks, both of East and West."

The two visitors did not stay five minutes with Mr. Buxton. They wished their visit to have the air of a mere passing call, and when he had shaken hands with them and wished them good luck, they left his rooms, strolled into Chancery Lane, and went gently up towards Holborn as if they had nothing to do but stare at the sights of the town like country cousins.

"Jack," said Buck softly, "let's pull up and look at this shop window, the panes have just got the bulge I want."

Jack, wondering a little what his companion meant, stopped, and they stared into a print shop where photographs of eminent judges and K.C.'s were set out in rows.

"Say, this is bully," murmured Buck. "Move a bit on one side, Jack, so that I can see the street behind us reflected in the glass. Now, come on, I've seen all I want. Don't turn your own head or you'll spoil the show."

They walked on together, and Buck muttered in deep satisfaction: "I've spotted the man following us; a stout chap with a double chin and a look like a fat policeman out o' work. I reckon I've tumbled to this game. I've seen him outside our hotel."

"Is it one of the gang?" asked Jack.

"Oh, no," replied his companion. "More likely to be one o' these private detectives hired to watch us. Now we've got to throw pepper into his eyes, an' then make a break for the station."

Buck raised his hand and hailed a growler. They got in, Buck said "Marble Arch," and away trotted the horse. Buck now set himself to keep a watch out of the little window at the back of the cab, and soon gave a chuckle of satisfaction.

"He's coming," he said, "he's in a hansom about fifty yards behind. This makes it a dead cert that he's our man. It would be a bit too much of a coincidence for him to be outside our hotel last night, following us up Chancery Lane to-day, and now tracking us along Oxford Street."

"How will you drop him?" asked Jack.

"As easy as tumbling off a log," replied Buck. "We'll use Connaught Mansions. Do you remember its two entrances? We'll pop in at one and out at the other."

Jack laughed, and understood at once. His father had a flat at Connaught Mansions, a huge block of flats near Lancaster Gate, which served as Mr. Haydon's London home between his journeys. They had made no use of it during the few days they had been in town, preferring a hotel near Mr. Buxton's rooms, but now it would be of service to their plans.

As they neared the Marble Arch, Buck gave the address to the driver. He handed up a couple of half-crowns at the same time.

"We may be detained at the place you're driving to," he remarked. "Wait a quarter of an hour at the door, and then if we don't send any message to you, you can go."

"Very good, sir," said the cabby, and on rolled the growler, and soon turned into the courtyard of Connaught Mansions, and pulled up at the main entrance. Jack and his companion left the cab at once and went into the lobby, where the porter came out of his office.

"Hullo, Mr. Risley, you are back again," said the porter. Then he caught sight of Jack, whose face was very well known from frequent visits to his father. The question which had plainly been on the porter's lips was at once checked. He had been eager to talk to Buck about the disappearance of Mr. Haydon, but Jack's presence put a barrier upon that.

The cloppety-clop of the feet of a passing cab horse now came in through the open door of the vestibule. Jack glanced out and saw the stout man passing in his cab. The spy seemed to be very busy reading a paper, and the whole thing looked as innocent as could be.

"Well, I'll nip upstairs an' get what I want," said Buck to the porter, and he and Jack rang for the lift, and were shot up to the fifth floor. Upon this landing there was one projecting window, which commanded the front of the great building, and the two comrades went cautiously to it and peeped out.

"There he is, there he is," whispered Jack.

"Sure thing," chuckled Buck.

Far below them they saw their cabman sitting idly on his perch and waiting for his quarter of an hour to pass. The Mansions looked on to a square, a long narrow strip of gardens, filled with lofty bushes rather than trees. The spy's cab had taken a sweep round these gardens and was now drawing up on the other side, exactly opposite their cab. As they looked they saw the stout man leave his cab and move to and fro till he found a space through which he could look across the gardens and watch the entrance to the great building. From their lofty standpoint Jack and his companion had a splendid bird's-eye view of everything.

"Off we go now," said Jack. "For if our cabman makes a move he'll become suspicious."

"We've got ten minutes yet," murmured Buck; "but as you say, Jack, off we go."

They turned and crossed the landing swiftly, and ran down the stairs, flight after flight. They did not wish to call attention to their movements by ringing for the lift; besides, they were making for the back of the place, where a smaller entrance opened on a quiet side street. They gained this and were once more free to strike where they wished, leaving the baffled spy to watch the main entrance in vain.