“But how did we escape?” I asked Feng.
“We were only in the nick of time,” he replied. “When Thelma disappeared from her husband in Gloucester Road I felt certain that she had been decoyed away. She was—by a message purporting to come from her husband asking her to call at Heathermoor Gardens. She did so and fell into the hands of the man who intended she should die. Yet so clever was old Humphreys, that, though I kept him under close observation, I could not discern that he was acting at all suspiciously. I did not know of course, of his plot to burn you alive. But we were watching him very closely. That night Stanley and I tracked him to the house at Hampstead. We saw you arrive later, but we little dreamed that Thelma was held there a drugged and helpless prisoner. She screamed twice, apparently, and you heard her, but some accomplice of Humphreys’ gave her a hypodermic injection—we found the mark afterwards on her arm.
“We watched until the first man-servant came out and later Humphreys himself left the place and walking in some distance away concealed himself in full view of the house. Then I knew you were left in there, and I became seriously alarmed.
“Fortunately a constable was near, and unseen by the old villain I approached him, told him of my suspicions, and we all three approached the house together. To our rings and knocks there was no answer, therefore we forced the door and rushed in. As we opened the door of the room where you were, we saw the air-ball burst and in a second the room was a furnace.
“Then came a desperate fight for life. Audley dashed to Thelma and succeeded in getting her out into the street at the cost of his own life, while I and the constable cut the rope which secured your wrists, and carried you out terribly burned and insensible. Both the constable and I were also burned, but not very seriously. Before the fire brigade arrived the house had been seriously damaged: but for our early warning it must have been utterly destroyed, as Humphreys intended.
“Meanwhile, Humphreys, who had seen the failure of his plot, made himself scarce and it was not until three days later that Inspector Cayley of Scotland Yard, with two sergeants traced him to a room in Earl’s Court Road, where he was hiding. But the old criminal had locked himself in and before they could break open the door he had put a bullet through his brain. A week ago both Ruthen and Graydon were arrested at the Pavilion Hotel in Boulogne on charges of passing spurious notes in various towns in France. They will, no doubt, go to hard labor for some years.”
“Well, Yelverton,” the old man concluded, “I think you know everything now. You have both had a very narrow escape from a terrible fate. Only a devil in human form could have devised such an atrocity. But now I’ll leave you alone for a bit: you will have plenty to talk about.”
And with a cheery smile and a loving look at Thelma, the sturdy, bearded old man, to whose watchfulness we both owed our lives, turned on his heel and left the room.
The calm Riviera sunset had deepened into twilight, swiftly as it always does, and the night clouds rising over the pine-clad Esterels cast their long grey shadows across the calm sea. Beneath our window twinkling lights shone and from among the orange graves below came voices and merry laughter.