The other book was more recent, and by an odd coincidence was a guide to the Greek islands. He thumbed through it idly and a piece of paper fell out.

«Earl Grey or Lapsang Souchong?» called out Reg. «Or Darjeeling? Or PG Tips? It's all tea bags anyway, I'm afraid. And none of them very fresh.»

«Darjeeling will do fine,» replied Richard, stooping to pick up the piece of paper.

«Milk?» called Reg.

«Er, please.»

«One lump or two?»

«One, please.»

Richard slipped the paper back into the book, noticing as he did so that it had a hurriedly scribbled note on it. The note said, oddly enough, «Regard this simple silver salt cellar. Regard this simple hat.»

«Sugar?»

«Er, what?» said Richard, startled. He put the book hurriedly back on the pile.

«Just a tiny joke of mine,» said Reg cheerily, «to see if people are listening.» He emerged beaming from the kitchen carrying a small tray with two cups on it, which he hurled suddenly to the floor. The tea splashed over the carpet. One of the cups shattered and the other bounced under the table. Reg leaned against the door frame, white-faced and staring.

A frozen instant of time slid silently by while Richard was too startled to react, then he leaped awkwardly forward to help. But the old man was already apologising and offering to make him another cup.

Richard helped him to the sofa.

«Are you all right?» asked Richard helplessly. «Shall I get a doctor?»

Reg waved him down. «It's all right,» he insisted, «I'm perfectly well. Thought I heard, well, a noise that startled me. But it was nothing. Just overcome with the tea fumes, I expect. Let me just catch my breath. I think a little, er, port will revive me excellently. So sorry, I didn't mean to startle you.» He waved in the general direction of the port decanter. Richard hurriedly poured a small glass and gave it to him.

«What kind of noise?» he asked, wondering what on earth could shock him so much.

At that moment came the sound of movement upstairs and an extraordinary kind of heavy breathing noise.

«That…» whispered Reg. The glass of port lay shattered at his feet. Upstairs someone seemed to be stamping. «Did you hear it?»

«Well, yes.»

This seemed to relieve the old man.

Richard looked nervously up at the ceiling. «Is there someone up there?» he asked, feeling this was a lame question, but one that had to be asked.

«No,» said Reg in a low voice that shocked Richard with the fear it carried, «no one. Nobody that should be there.»

«Then…»

Reg was struggling shakily to his feet, but there was suddenly a fierce determination about him.

«I must go up there,» he said quietly. «I must. Please wait for me here.»

«Look, what is this?» demanded Richard, standing between Reg and the doorway. «What is it, a burglar? Look, I'll go. I'm sure it's nothing, it's just the wind or something.» Richard didn't know why he was saying this. It clearly wasn't the wind, or even anything like the wind, because though the wind might conceivably make heavy breathing noises, it rarely stamped its feet in that way.

«No,» the old man said, politely but firmly moving him aside, «it is for me to do.»

Richard followed him helplessly through the door into the small hallway, beyond which lay the tiny kitchen. A dark wooden staircase led up from here; the steps seemed damaged and scuffed.

Reg turned on a light. It was a dim one that hung naked at the top of the stairwell, and he looked up it with grim apprehension.

«Wait here,» he said, and walked up two steps. He then turned and faced Richard with a look of the most profound seriousness on his face.

«I am sorry,» he said, «that you have become involved in what is… the more difficult side of my life. But you are involved now, regrettable though that may be, and there is something I must ask you.

I do not know what awaits me up there, do not know exactly. I do not know if it is something which I have foolishly brought upon myself with my… my hobbies, or if it is something to which I have fallen an innocent victim. If it is the former, then I have only myself to blame, for I am like a doctor who cannot give up smoking, or perhaps worse still, like an ecologist who cannot give up his car — if the latter, then I hope it may not happen to you.

What I must ask you is this. When I come back down these stairs, always supposing of course that I do, then if my behaviour strikes you as being in any way odd, if I appear not to be myself, then you must leap on me and wrestle me to the ground. Do you understand? You must prevent me from doing anything I may try to do.»

«But how will I know?» asked an incredulous Richard. «Sorry I don't mean it to sound like that, but I don't know what…?»

«You will know,» said Reg. «Now please wait for me in the main room.

And close the door.»

Shaking his head in bewilderment, Richard stepped back and did as he was asked. From inside the large untidy room he listened to the sound of the Professor's tread mounting the stairs one at a time.

He mounted them with a heavy deliberation, like the ticking of a great, slow clock.

Richard heard him reach the top landing. There he paused in silence.

Seconds went by, five, maybe ten, maybe twenty. Then came again the heavy movement and breath that had first so harrowed the Professor.

Richard moved quickly to the door but did not open it. The chill of the room oppressed and disturbed him. He shook his head to try and shake off the feeling, and then held his breath as the footsteps started once again slowly to traverse the two yards of the landing and to pause there again.

After only a few seconds, this time Richard heard the long slow squeak of a door being opened inch by inch, inch by cautious inch, until it must surely now at last be standing wide agape.

Nothing further seemed to happen for a long, long time.

Then at last the door closed once again, slowly.

The footsteps crossed the landing and paused again. Richard backed a few slight paces from the door, staring fixedly at it. Once more the footsteps started to descend the stairs, slowly, deliberately and quietly, until at last they reached the bottom. Then after a few seconds more the door handle began to rotate. The door opened and Reg walked calmly in.

«It's all right, it's just a horse in the bathroom,» he said quietly.

Richard leaped on him and wrestled him to the ground.

«No,» gasped Reg, «no, get off me, let me go, I'm perfectly all right, damn it. It's just a horse, a perfectly ordinary horse.» He shook Richard off with no great difficulty and sat up, puffing and blowing and pushing his hands through his limited hair. Richard stood over him warily, but with great and mounting embarrassment. He edged back, and let Reg stand up and sit on a chair.

«Just a horse,» said Reg, «but, er, thank you for taking me at my word.» He brushed himself down.

«A horse,» repeated Richard.

«Yes,» said Reg.

Richard went out and looked up the stairs and then came back in.

«A horse?» he said again.

«Yes, it is,» said the Professor. «Wait» — he motioned to Richard, who was about to go out again and investigate — «let it be. It won't be long.»

Richard stared in disbelief. «You say there's a horse in your bathroom, and all you can do is stand there naming Beatles songs?»

The Professor looked blankly at him.

«Listen,» he said, «I'm sorry if I… alarmed you earlier, it was just a slight turn. These things happen, my dear fellow, don't upset yourself about it. Dear me, I've known odder things in my time. Many of them. Far odder. She's only a horse, for heaven's sake. I'll go and let her out later. Please don't concern yourself. Let us revive our spirits with some port.»

«But… how did it get in there?»

«Well, the bathroom window's open. I expect she came in through that.»