ubject quickly.

"Have you heard from Poltavo this morning?"

"Nothing at all," said Fall; "he has been communicating with somebody or
other, and the usual letters have been passing. Our man says that he has
a big coup on, but upon that Poltavo has not informed us."

"If I thought he was going to play us false----"

"What would you do?" asked Fall quietly. "He is out of our hands now."

There was a little buzz in one corner of the room, and Fall turned his
startled gaze upon the other.

"From the signal tower," he said. "I wonder what is wrong."

High above the house was one square solitary tower, in which, day and
night, a watcher was stationed. Fall went to the telephone and took down
the receiver. He spoke a few words and listened, then he hung up the
receiver again and turned to Farrington.

"Poltavo is in Great Bradley," he said; "one of our men has seen him and
signalled to the house."

"In Great Bradley!" Farrington's eyes narrowed. "What is he doing here?"

"What was his car doing here the other day," asked Fall, "when he
kidnapped Frank Doughton? It was here to throw suspicion on us and take
suspicion off himself, the most obvious thing in the world."

Again the buzzer sounded, and again Fall carried on a conversation with
the man on the roof in a low tone.

"Poltavo is on the downs," he said; "he has evidently come to meet
somebody; the look-out says he can see him from the tower through his
glasses, and that there is a man making his way towards him."

"Let us see for ourselves," said Farrington.

They passed out of the room into another, opened what appeared to be a
cupboard door, but which was in reality one of the innumerable elevators
with which the house was furnished, and for the working of which the
great electrical plant was so necessary.

They stepped into the lift, and in a few seconds had reached the
interior of the tower, with its glass-paned observation windows and its
telescopes. One of the foreign workmen, whom Farrington employed, was
carefully scrutinizing the distant downs through a telescope which stood
upon a large tripod.

"There he is," he said.

Farrington looked. There was no mistaking Poltavo, but who the other man
was, an old man doubled with age, his white beard floating in the wind,
Farrington could not say; he could only conjecture.

Dr. Fall, searching the downs with another telescope, was equally in the
dark.

"This is the intermediary," said Farrington at