“Never mind about the sentence,” I answered quickly. “I shall have to serve that—and not you! But there won’t be any sentence, because there won’t be any capture—if you help me. And you are going to help me. Oh, yes, you are.”

We both laughed.

“You are a one, sir—an’ no mistake!” he exclaimed. “Well, yes, I’ll do me best and charnce it. I’m a bit of a sport meself when they gives me arf a charnce.”

And so it was settled. It was this policeman’s duty to keep an eye on Crane’s Alley, which was included in his beat. Well, he would for once forget to keep an eye on it, while the sergeant was out of the way. More, he would lend a hand when the time came to force the lock of the door in the little yard. After that he would be at liberty to slip back to Belgrave Street and resume his monotonous tramp.

And all this would happen on the following night, or rather, about two o’clock next morning.

When I left him it was nine o’clock, and, feeling in high spirits, I drove to the Grand to tell Vera my plan, for I felt I must tell somebody. She was alone in the private sitting-room overlooking the thousand lights of Trafalgar Square, and I sat with my arm about her.

“It is madness—sheer madness,” she exclaimed, when I had outlined my scheme, “and if you will take my advice—you know my advice is generally sound—you will at once abandon the idea, Dick. It is very well for you to say that my father is your friend, but you don’t know my father—you don’t know him as I know him. There are two sides to his character. Indeed, I would say he is really two men in one. The man you know is very different from the other man—my father as you have never seen him, and as I hope you never will see him. He can become perfectly savage. He has a temper that is altogether unmanageable when once it gets the better of him. It doesn’t often, but when it does—

“No, don’t do it, dear, don’t, I beg of you. I ask you not to. I beg you not to if you really love me.”

“I must,” I answered, with a firmness that surprised her. “I have gone too far now to draw back, even if I wanted to, which I don’t. I am going to see this thing through. I’m going to discover the mystery of that house. I don’t care what risks I take, or what happens, but I am going to see for myself what all this secret business means.”

To my surprise she began to laugh.