‘You’re making this all up,’ Aiden said. ‘This is all lies.’

‘Well, let’s see what happens next. Let’s imagine that you’ve decided that you’re not going to play along with what Frank has demanded. Instead, you’re going to get rid of this sick pervert once and for all. And you’ve got the perfect fall guy to take the blame.

‘You go to the party which Lawrence and Pauline have thrown for the staff. Cecily was taking sleeping pills – diazepam – and it would have been easy for you to steal a few of them and spike Stefan’s drink. When he went to bed that night, he was drugged, not drunk. The following morning he was bleary-eyed. He would have slept through anything.

‘Cecily had also taken a pill and she was asleep when you crept out for your midnight assignation. It was important to you that Stefan should be seen entering room twelve, but you had it all arranged. You collected the toolbox from the maintenance shed and put on a beanie just like his. You went in through the front door and took the lift up to the second floor. Derek Endicott was sitting in the reception area down below. How were you going to get him upstairs to see you?

‘The answer was Bear, the dog. My guess is that you used the Irish brooch that sits on the table beside the basket.’ I had it in my handbag and took it out, then unclasped the needle, which was about two inches long. I placed it on the table in front of Locke. ‘When this is all over, maybe you should have it analysed, Detective Chief Superintendent. There should still be traces of Bear’s blood. I think Aiden jabbed it into him and that’s why he barked.’

I turned back to Aiden.

‘So, Derek comes up to see what’s wrong. He’s kneeling to examine the dog and you flit past, going along the corridor towards room twelve. It’s dark up there. He barely has time to see anything: just the beanie and the workbox. Of course, he assumes it’s Stefan. Even so, he goes across to the corridor to see but by the time he gets there – only a few seconds – the man has disappeared. What does that tell us? Derek doesn’t hear anybody knock. He doesn’t hear voices. No explanations or greetings or anything like that. Frank might have propped the door open using a waste-paper basket or something, but I think that’s unlikely. Part of the fun was Leo letting himself in and of course he has a key.

‘You’re in room twelve. Frank is waiting for you. You wait until Derek has gone back downstairs. And then you take out the hammer and beat Frank to death so violently that come the next day, he will be unrecognisable. There was a lot of anger in this murder. I knew that from the start. And you had every reason to be angry.

‘But the night wasn’t over yet. You took money from Frank Parris’s wallet and you also needed some of his blood to sprinkle onto the bedclothes and the shower in Stefan’s room. I think that’s why you stole Lawrence’s fountain pen, which had never been used and which wouldn’t contaminate the blood sample. You used the reservoir to suck some of Frank’s blood into the pen and then you took it, along with the money, to the stable block. There was a duplicate key in Lisa’s office and it would have been simple for you to get hold of it too. Stefan wouldn’t wake up. He was still drugged, sound asleep. He didn’t hear the door open. He didn’t see you hide the money and spray a few drops of Frank’s blood. After that, you got rid of the pen and went back to bed.

‘Let’s not forget the “Do Not Disturb” sign. You had killed Frank because he threatened your marriage to Cecily. It was essential to you that the marriage went ahead. That’s why you put the sign on the door after the murder. Presumably, you got Stefan’s fingerprints onto it while he was asleep. And then sometime after the service and before the big party, you must have taken it down again. Why did you do that, Aiden?’

‘I’m not answering any of your questions.’

‘Well maybe it was because you didn’t want to go on the honeymoon. After all, you didn’t love Cecily. I don’t think you even liked her. My guess is that you married her for the money and the security and the life of a country squire. Maybe it even gave you a kick, ruining her big day.

‘And you almost got away with it. Except that a few weeks after the murder a writer turned up at the hotel looking for a story and it was your bad luck that he found you.

‘Alan Conway recognised you too, didn’t he? That’s why you were reluctant to talk to him. I’ve listened to the tape he made when he was talking to Pauline and what’s the first thing he says when he sees you? “We’ve already met.” At that moment, everything makes sense for Alan. He knows who the killer is and in his own way he’s taunting you just like Frank did a few weeks before. Of course, you have to try to cover yourself. “Yes. I was in reception when you arrived,’ you explain, for the benefit of Pauline. But then what does he say a few moments later? “Please, call me Alan.” And you reply: “I’m not playing this game.” Because that’s what it is, isn’t it? An unpleasant game. You both knew the truth. You’d met over dinner in London … and Frank Parris was at the table too!

‘Nothing happens now for eight years. Alan has disappeared and you probably heave a sigh of relief when you hear he’s dead. Maybe you’ve glanced at what he’s written, but on the face of it Atticus Pünd Takes the Case has got nothing to do with Branlow Hall. You think you’ve got away with it.’

I took another sip of water. Everyone in the room was silent, watching me, waiting for me to continue. Only one of them – Locke – was sitting there with his eyes fixed on Aiden, realising what he had done and perhaps even what it might mean for his future career.

I put down the water. Out of the corner of my eye, I saw Andreas give me a smile of encouragement. I went on.

‘Then Cecily reads the book.

‘Let me go back to what I know of her character. Lawrence told me that she was too good-natured, too trusting, the sort who believes the best in everyone. He was talking about her relationship with Stefan but he could just as well have been referring to her relationship with you. Melissa Conway even compared her to Dora in David Copperfield. I think Cecily went into her marriage with the same innocence. She had no idea what she was getting into.

‘But she found out soon enough. I don’t know what it must have been like living with you, Aiden, but she must have known you weren’t quite the Prince Charming of her dreams. Even in the early days when you were engaged, you obviously weren’t up to much in the bed department because she was having to satisfy her needs with Stefan. And later on? Women are intuitive. We sort of get the idea when we’re married to a homicidal maniac.

‘But even if she suspected that you killed Frank Parris she still had no evidence – mainly because you had no reason to. You’d never even met him. So what happens when she opens the book and she sees the dedication – “For Leo and Frank”? If Aiden is Leo than suddenly everything that happened during Frank’s visit – his strange behaviour, his lies – makes some sort of sense. And let’s not forget that’s exactly what you were to her. The beloved Leo to her Sagittarius.’

‘Aren’t you forgetting something?’ Aiden looked at me defiantly. ‘I was the one who gave her the book. I read it before she did. I told you that.’

‘That’s what you said to me, Aiden. That’s what you wanted me to think because it made you look innocent. The book identified the true killer of Frank Parris, so whoever the killer was, he’d be the last person to let Cecily see the book.

‘But the truth is, by the time I arrived at the hotel, you hadn’t even read it; at least not all of it. Of course, you wanted to. You had to know what was in it – what Cecily had seen. But you had difficulty getting hold of a copy because, as it happened, there had been a major glitch at the distribution centre in Didcot. I actually met the publisher and he told me that nobody had been able to get hold of Atticus Pünd Takes the Case for about two months. The copy that you showed me was brand new and my guess was that it had only arrived a day or so before I did and you’d only just started it. When I asked you if you’d enjoyed it, you described it as twisty and said the ending had a sucker punch. But those weren’t your words.’ I picked up the paperback and handed it to Lawrence. ‘If you look at the reviews that are printed at the beginning, you’ll see that the Observer described it as twisty and the author Peter James said it had a sucker punch. I used to meet a lot of people in publishing who did the same. They pretended they’d read the book when in fact all they’d done was glance at the crits.’ I glared at Aiden. ‘You’d got as far as page 20. That’s where Algernon turns up. You didn’t have a clue what happened next.’