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 swi