There was no answer.

“She, too, by thunder!” he growled, rattling the handle. The door was locked.

“Your shoulder, Jefferies!” and for the second time in half an hour French burst open the door of a bedroom. As in the former case, the room was empty.

But here there was no open window. Not only was the sash latched, but when French opened it and looked out he found that it was thirty feet above the pavement and that there was nothing to assist a descent.

A glance at the door explained the mystery. The key was missing. Evidently the occupant had left the room by the door, locking it behind her and removing the key. And the maid was able to supply the further information required. The girl, on coming down that morning, had found the yard door unlocked. Though she thought she had fastened it on the previous evening, she had supposed she must have overlooked it.

French hurried down the narrow yard to the door which led out on the passage behind the houses, only to find that here again the door was locked and the key missing. Again and again he cursed himself for having underestimated the ability of these two people. Had he had the slightest idea that they had followed his progress so minutely, he would have employed very different methods. Even if he had not arrested them, he would have seen to it that they did not escape. The shadowing he had adopted would have been effective under normal conditions, but not where the victims were alive to their danger and ready to make a desperate bid for safety.

But French was too sensible to cry over spilt milk. He had blundered. Very well, it could not be helped. What he had to do now was to retrieve his error, at the earliest moment possible. How could he most quickly get on the track of these criminals?

He returned to the house and made a rapid search for any clue that the lady might have left, but without result. Then leaving Jefferies in charge, he drove back to Kepple Street.

Chapter Nineteen: The Bitterness of Death

“Any luck, Carter?” French asked, quietly, as he reëntered Pyke’s room.