At four o'clock there was a knock at the door. I went slowly down the stairs to answer, and could see through the glass of the door the outlines of two uniformed figures. It was the police. I took a deep breath, but why should I be scared? Everything was perfectly hidden. I opened the door, and the two officers told me that a neighbour had called 999 having heard a loud scream from my house earlier. I smiled, I was totally relaxed. "Ah," I said, "that was me, I'm afraid. I suffer from terrible nightmares - I do sometimes cry out."

They looked unconvinced, so I invited them in. "Feel free to look around," I said. "My lodger is away at the moment, but you're welcome to look around any room in the house." I then showed them over the entire house, confident that there was nothing which could arouse their suspicion. Finally we came back down to the hall. there was no chance I would be caught, so, for the sheer delight of it, I offered the men a drink - you see, I have a drinks cabinet in the hall.
"Gentlemen, a drop of scotch for you before you go- it's a cold night out there."
They looked at each other - obviously they were not meant to drink on duty - but my offer tempted them, I could see.

As I was pouring the drink, I felt something on my skin. A light tapping, like a fingertip. I steadied my hand - this was unnerving. I stared at the liquid in the glass - I could still feel the tapping, but now, now i could see - there were ripples, regular, rhythmic ripples, across the surface of the drink in the glass; tap tap; tap tap; tap tap. I handed the drinks to the officers, trying hard to stop my hand from shaking. I could feel it through the air now, a thud ,a tap - but double, like a heartbeat. the officers took their drinks thanked me. I began to talk more loudly. The thumping was getting worse - it was a tremor now, I could feel the dreadful double beat through my feet.