I’m in the drawing room with the Great Detective. We all are – all the family, the household staff, the weekend guests, anyone who’s been involved right from the start of this puzzling affair. We’re all suspects and we know it. We’ve each of us had to put up with a questioning and a cross examination from the man himself, as well as the more mundane, clumsy prodding of the local constabulary. Nobody, its fair to say, has particularly enjoyed the process. The air in here is positively bristling with indignation, everyone is just bursting to stand up and protest their innocence, to express their resentment at having to put up with such a charade. In truth, we should be grateful to be here. It’s not everyone who gets a front row seat for a show like this. Tonight after all we will be watching a master at work. This is the scene in the play where he lines everyone up and unravels the mystery for us. This is the moment where he explains exactly what has been going on, displays every facet of his ingenuity before eventually, finally pointing out which one of us murdered poor old Aunt Charlotte last Friday evening.

God only knows how he gets away with it. You’d have thought there’d be rules against this sort of thing. Other people have to play it by the book, to follow procedure and whatnot, but none of that seems to apply to him. He makes his own rules, so they say, by being a genius and by virtue of always, irritatingly, inevitably solving the crime. There is no puzzle, they say, that the great man cannot unlock, no code he cannot break. If there are jewels to be found, he will find them. If there is a plot to be stopped, he will stop it. Reading his press he comes across like some sort of Neitzchean superman with a monocle and a waistcoat who always, always gets his man.

All of which is a little bit worrying for me at this stage, to be honest. What with me being the culprit and all, it is a little disconcerting to have to sit here and watch him explain, in great detail and with no little flair, exactly how it was I managed to pull the thing off. Very worrying.

So far, he’s got everything pretty much spot on. The motive – Aunt Charlotte’s money, of course, and her continual threats to put an infuriatingly un-family-friendly codicil in that valuable old will of hers. The method – arsenic in the hot chocolate (I am so fond of the classics). The misdirection – putting the poison into Charlotte’s secret brandy stash too, so as to make it look as though the murder might have taken place much earlier than it actually did. I have to say I’m very impressed. Even here, in my situation, knowing that things can’t possibly end well for me this evening, even I can’t help but admire the skill with which he’s picked it all apart. He’s even unravelled that little bit of double bluff I set up by planting the arsenic bottle in my own luggage (but cunningly making it look as though young Emma – the waiflike maidservant who, it turns out, has been having a dalliance with Cousin Stewart – must have put it there).

Yes, there’s no denying it. He’s seen right through every one of my deceptions. It’s only a matter of time before the finger turns and points my way. I should be upset, I know, but somehow I can’t quite summon up the energy. I’m just enjoying the show too much, waiting to see exactly how he’s going to pin me down. No doubt I made some shoddy mistake somewhere along the way that he’s going to have picked up on, that’s the way these things normally pan out. I’m sure that whatever happens I’ll completely deserve everything that comes my way. I’m not asking for any sympathy. I am guilty after all, there’s no question about that.

So I’m sitting back in my chair, quite relaxed and resigned to my fate when he comes to summing things up and prepares to unveil the killer. I’m not even listening properly anymore. So confident am I about what’s coming next that I’ve already begun to mentally prepare my confession and my congratulations to the sleuth. Something suitably witty and self-deprecating I’m thinking. Something sharp with a little bit of style. If one has to go to the gallows, one might as well be cheerful about it, that’s what I say.

You can imagine my surprise then, when his voice rises to a crescendo, a peak of flamboyant outrage and, standing right in front of me, he spins and stretches out a finger and declares the murder to be none other than…Great Uncle Malcolm? Really? That decrepit old codger in the wheelchair here beside me? Can he be serious?

At first I can’t believe it. It doesn’t seem possible that he’s made such an obvious blunder. I’m waiting for him to crack a joke and turn his glare in my direction, but he never does. Instead, to Uncle Malcolm’s horrified indignation, he runs through all the evidence that proves indisputably that he is the only one of us who could possibly have committed the crime. I’m glad to say that it does all sound very convincing. So much so that I begin to wonder whether I’m not the only murderer in the room. Maybe we both did it? Who knows? Either way it seems like I’ve pulled it off. Managed to trick my way past the Great Detective and all his bloodhounds.

In my jubilation I find myself having to fight an urge to stand and shout, “You’re wrong! You’re so wrong!” and glory in the fact that I’ve beaten the master on his home ground, but I manage to retain just enough self control to remember how much that would not really be in my best interests. Better to sit tight and try to suppress that grin. Take a deep breath and try to think of all those riches that are coming my way.

I sit back in my chair and try to figure out a way to force my heart to stop beating so fast. Everyone else in the room looks sick and drained, as if they’re being dragged through an emotional wringer. For the first time this weekend I almost feel sorry for them, begin, even, to wish I hadn’t had to put them through it all. Cousin Stewart is on his feet and shaking his fist, arguing bitterly with the detective and his sidekicks. The maids are all weeping uncontrollably. Over in the corner Aunt Sophie is turning a very unhealthy looking pale yellow sort of a colour. Poor Aunt Sophie, with her bad legs and weak heart. This weekend’s affair can’t have done her any good at all. She probably doesn’t have long left, really. Much more of this and she’ll probably tip right over the edge, no doubt. She lurches forward in her chair and daps at her mouth with a handkerchief. She’s looking right over to me, her eyes pleading as though she wants my help, needs me to do something to make it all right. I get to my feet and take her over a glass of water. As her frail old hand takes it from me and she nods her thanks, I find myself beginning to wonder just how, exactly, the contents of her will are arranged?