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 last. They watched the meeting, saw the exchange of the letters, and Farrington uttered a curse. Then suddenly he saw the other leap upon Poltavo and witnessed the brief struggle on the ground. Saw the glitter of handcuffs and turned with a white face to the doctor. "My God!" he whispered. "Trapped!" For the space of a few seconds they looked one at the other. "Will he betray us?" asked Farrington, voicing the unspoken thoughts of Fall. "He will betray us as much as he can," said the other. "We must watch and see what happens. If he takes him into town, we are lost." "Is there any sign of police?" asked Farrington. They scanned the horizon, but there was no evidence of a lurking force, and they turned to watch T. B. Smith and his prisoner making their slow way across the downs. For five minutes they stood watching, then Fall uttered an exclamation. "They are going to the cottage!" he said, and again the men's eyes met. "Impossible," said Farrington, but there was a little glint in his eye which spoke of the hope behind the word. Again an interval of silence. Three pairs of eyes followed the men. "It is the cottage!" said Fall. "Quick!" In an instant the two men were in the lift and shooting downwards; they did not stop till they reached the basement. "You have a pistol?" asked Farrington. Fall nodded. They quitted the lift and walked swiftly along a vaulted corridor, lighted at intervals with lamps set in niches. On their way they passed a door made in the solid wall to their left. "We must get her out of this, if necessary," said Farrington in a low voice. "She is not giving any trouble?" Dr. Fall shook his head. "A most tactful prisoner," he said, dryly.