Then I stood her up again and stepped away from her. She looked like a wax dummy on its stand that you see in any dressmaker’s shop.

All this had taken about ten minutes and I had to hurry. I put some more adhesive tape round her mouth and fastened her arms to the table legs. I didn’t think, if she did come to the surface, she could move or attract attention.

Then I covered her with one of the sheets and tied the sheet round her waist with a length of string. I did exactly the same with the dummy.

Side by side, under the sheets, you couldn’t tell which was the dummy and which was Lydia.

Now the tricky part of the business began. The apartment house was divided into wings. We lived in the West wing and each wing was connected by a long corridor. There were four entrances all leading out to the same street, so the copper who was watching outside could see all entrances at once.

But I reasoned this way. He saw me go in with Lydia by the West entrance. He knew I was wearing a dark suit. I had to hope that if I came out of the North entrance with a light suit on he might not connect me with the guy he saw going in the West entrance. Anyway, that was how I had to play it.

I picked Lydia up under one arm and the dummy under the other. Together they were plenty heavy, but I managed. I walked out of my apartment down the corridor, until I came to the North hall. I left Lydia and the dummy there and giving my bat another jerk over my face, I walked out into the street.

I felt as if every eye in the police force were watching me. I glanced right and left. The cop, who’d parked himself outside the West entrance was moving slowly towards me. He wasn’t suspicious, but I guess he just wanted to make sure.

I turned and walked very slowly towards him. I saw him hesitate and then turn back to the West entrance. Who said that attack wasn’t the best form of defence?

I looked back over my shoulder and then paused on the curb. When a taxi passed, I yelled and the driver crammed on his brakes.