I did it. Elliot John Bartlet. Me.

Oh well, so much for the mystery. I poisoned her, bit by bit, and got my timing so accurately that she collapsed on stage just as the curtain was closing. The audience didn't see her crumple and fall into the arms of Philip, who had just played Gregg (in "Relatively Speaking", by Alan Ayckbourn). It wasn't her best performance, her last. But I couldn’t do anything about that. She was terrible in everything she was in anyway, and tonight was no exception. I was brilliant, playing Philip (god, that got confusing) with my advanced theatre skills and, as I've said, good timing and actorly projection to the back of the hall. I was a tour de force. And tonight, I pulled off the best performance of my life - as the newly widowed, grieving husband.

Ellie didn't suffer. Much. The poison gave her a few belly aches, but that was all until I administered the last fatal dose in Act 2, Scene 3.

A cup of cold tea. It probably did taste exactly like poison (almonds), but you have to carry on, in front of an audience. Can't complain about the taste when you're in the middle of Act 2.

We await the post-mortem, of course, and here is Act Two of my own play. I know the pathologist, and we get on so well that she's waiting for me in our little cottage by the sea, even now. She'll come up to town in a few days, do the necessary faffings and pokings about and eventual signings of "Heart attack, been brewing for some time" etc. I've been laying it on a bit thick in rehearsals, hinting at a dodgy ticker, asking people to keep an eye on Ellie, look for signs. I even got another one of my good friends, a doctor, to have a word with her. He told Ellie to "be careful" and suggested that she take an aspirin every now and then.

Ellie, in her ditzy way, ignored all that. She was very, very annoying. Liable to say whatever came into her head at any moment, in any company. Her casually telling the whole cast in rehearsals that I couldn’t get it up any more, her giggling at any word in the play she thuought rude, her relentless chatter with no filter, her casual and pretty obvious flirting with Philip, twenty years her junior, her low cut dresses and push-up bras, her bright red lipstick, her stinky perfume, her refusal ever to make the tea, or bring biscuits, or help with clearing up after rehearsals, her inability to learn lines, her blatant disregard for the most basic rules of theatre - I could, and will, go on. She had to go.

She was cast in every play we did. Even when I managed to get an all-male play put on, she would suggest that a minor female character was what the playwright really wanted, so she cast herself in it and gave herself some lines (which changed every week) and plonked herself into the production.

We have a director, Jeremy. As useless as an ashtray on a motorbike, he adored Ellie, but Ellie didn't notice him at all. Certainly didn't take any direction from him, not that he eventually gave her any (Ellie - giggle!). It will be tough on Jeremy now that she's dead.

The poison was cyanide. I know a bloke who works in the chemistry department at Leeds University. I used to work there, and I have a PhD in Chemistry. I knew what I was doing. Easy, really, if you know the ropes. Research, that kind of thing. A paper which will never be published, all that.

The idea came to me when we were doing Arsenic and Old Lace, one of Agatha Christie's best, I think. Arsenic is a bit trickier to come by, but that was the idea. Except I just wanted to bump off one person, not have a pile of bodies around the place. Eventually, the old biddies were caught because they'd done it a few too many times, but I've no intention of bumping anyone else off; my work is done.

Now to look forward to a new life with my one love - Janice, the pathologist, in our little cottage by the sea, with its bracing walks and wonderful countryside, a proper breath of fresh air! I shall do the mourning thing in the meantime, wear black and mooch about, try not to laugh much, always have a tear in my eye ready. The funeral will be tricky, but Ellie being cremated will help me achieve closure, because the evidence will get destroyed too.

About the evidence - the bottle, the cup, and all are in a safe place - guess where? In the coffin! They will all go up in smoke. I've arranged to be there when the lid is closed. Her “favourite cup”, her “old bottle from her childhood”, will be sent with her on her way to the heavens. All cleaned out, of course, with a special chemical that I'm not even going to mention here.

I thought I'd write all this down because I want to be able to count off the days, weeks, months, and hopefully years before someone suspects something, as they probably will. There's no time limit on murders. It's a confession, sure, but these sorts of writings don't always stand up in court. I'm not well, in my head, so I've been telling my doctor friend and a couple of more expensive therapists. I may have to call on them at some point in the future, as evidence of my mental state at the time of the murder. I may get away with diminished responsibility. Or extreme provocation. So I’m putting down as much as I can here about Ellie and me at this time, it may be useful evidence in the future.

I'm writing this on my computer, all password protected and unhackable. A friend of a friend gave me some software to help with that. All very confusing to me, though I can't see this file nor the software anywhere on the computer screen. I have to type in some weird hieroglyphics in a “DOS Window”, whatever DOS stands for.

It was love at first sight, me and Ellie. We married after only seven months of meeting, and it was a proper whirlwind. We went abroad, skiing in the Alps, hiking in Yorkshire, shopping in New York, paragliding, windsurfing, everything outdoorsy, and had a fabulous time, and no time for kids, thankfully. Then we got left a huge legacy from my Uncle Jim, millions of pounds I didn't know he had - all left to me - and, because we were married, Ellie too.

But that amount of money wasn't good for us; we retreated into ourselves and stayed at home, not doing much. We didn't need to work to earn enough for our holidays any more, and the life pretty much went out of us. One evening, we managed to drag ourselves out to see a show by the local AmDram group, and a bit of a spark returned. We both joined up and were immediately cast in the next play - The Government Inspector, by Gogol - a very old Russian play which has stood the test of time. I was the postman, Ellie was the mother, and Janice (the pathologist) played her daughter. It was fabulous fun. But then it all started.

The little niggles that I hadn't noticed in Ellie began to get more obvious - see list above. We drifted apart, even though we lived in the same house. We only saw each other at rehearsals. We had a big house, so it was easy to live separate lives.

It all started, though, when Ellie got the lead and only role in the Vagina Monologues. She became impossible. She would wander into my half of the house, sometimes completely naked, and start taunting me, playing about, and pretty much acting like a spoilt child. Demanding role plays, making me do crazy things, like she was possessed by something. I tried to reason with her, asked her to calm down, but this sent her off even worse. I got her an appointment with a therapist, and surprisingly, Ellie went to see her. The therapist dismissed Ellie as not having anything she could do. Perhaps, in some ways, Ellie could be a good actor. After that single therapy session, she started harassing me, shouting and screaming at me for no reason, throwing cups to the floor, straight from the cupboard, and telling me how useless I was at everything, a proper coercive control.

She held it together at rehearsals, almost. It wasn't obvious to the rest of the cast that something was wrong with us. I considered divorce. I went to see a solicitor to start it all off, and had a letter sent to Ellie that I was considering it if her mood didn't change. That was a huge mistake. I spent two days locked in one of the bedrooms, with the door barricaded. She got a ladder and smashed the window to get in (with a fish knife of all things, I didn’t know we had a fish knife!). I eventually talked some sense into her, and she calmed down without bashing me with anything. I had the window pane fixed by the best local glazier, but it still looked slightly different from the others.

She had to go, and she's gone now, and that is ALL GOOD!

The police took all of our statements, of course, and I was too shocked and horrified to say much (as I said, I can act), and they seem to have left me alone with my grief. The suspicion of murder doesn't seem to have been thought about, and the local newspaper just mentioned it on page 8 : "Actor dies on stage, audience shocked", though the audience wasn't even aware of it. Journalists eh?

I've thought about several ways to bump her off, but I think that this one (quite simple and almost painless) was the best. Getting my ducks in a row with the doctor, the undertakers and the lovely Janice was a bit of a breeze, and the cops suspect nothing. The perfect murder.

I do have a little inkling that Ellie had found out about Janice, but Ellie's moods would swing so violently that she accused me of having affairs all the time. Even with the milkman. He's a handsome chap, alright, but not my type! Perhaps she had a thing with him? That wouldn't surprise me, and I didn't care either, especially if it would have kept her occupied.

Janice is a soothing, calm oasis of joy for me. Life is so different with her, it's almost unbelievable that someone could love me and not throw things at me at the same time. It is taking a lot of (pleasurable) adjustments, I can tell you. We met at the theatre, and started the affair just after the end of a run of Run For Your Wife (a story about a bigamist- ha!). We were in the car park, late after the last night, just chatting, when she grabbed me and kissed me. Ellie had gone home in her own car - we travelled to the shows separately by then. And so that was it: clandestine, awkward, tingling, exciting, exhilarating!

I bought our little cottage on the quiet. I opened a bank account in my own name, transferred a lot of money into it and made the purchase under the radar. I probably paid too much for it, but I wanted a quick sale. I even paid for some of the furniture, which was going to be auctioned off anyway. The old dear who lived here had died, and the family was quickly asset-stripping her stuff. Pretty good stuff actually, and it means we've no need to buy the basics.

So, I said up top that Ellie was "ditzy" - she was in the theatre, but at home she was anything but.

I think that's enough detail, I shall keep this. As long as this hiding software still works, I may need to come back to it. Hopefully not at all, but it might be something I can tell my grandchildren on my deathbed. Yes, Janice is expecting.