I’ve just got back from the Manchester Literature Festival, where I was reading at the launch of the anthology When It Changed, which has just been published by Comma Press. It was a surreal, wonderful weekend in which the mathematician Alan Turing was a recurring motif.

The strangeness started in the train on the way up, where there were people dressed as Star Wars characters – including an impressive Admiral Ackbar. Then I got to Manchester too early to check into my hotel room, and having changed my mind about wearing a t-shirt under my shirt, had to get changed in the lobby toilets. A guy staggered in and then practically weeped through a violent explosion of diarrhoea. So abject.

The launch was the first event of the day – it was great to meet up with Geoff Ryman, the editor, Patricia Duncker (another contributor), Dr Tim O’Brien and Prof Steve Furber – two of the scientists who collaborated on the collection. We all read sections from our stories and then did a Q&A, which brought back memories about the brilliant day I spent with Dr Vinod Dhanak the nano-scientist, earlier this year, and which inspired my story in the collection. Geoff read from Liz Williams’ story, as she couldn’t be there. It features a conversation between Wittgenstein and Alan Turing (the day’s first occurrence of Turing). All the copies of the collection at the venue sold out in an hour.

I stayed at the festival for the rest of the day to see the other events – so much great stuff: Bernard MacLaverty, David Constantine, Chris Beckett (whose book is called The Turing Test – Turing occurrence number two), James Lasdun and then two very humbling readings – Atef Abu Saif who was unable to appear in person as he’d not been granted a visa to leave Gaza, but who appeared in an interview which was recorded a couple of days earlier during one of the infrequent bursts of electricity they get there, and Hassan Blasim, a refugee from the Iraq war who has seen some horrific stuff, which he writes about using fantasy and black humour.

In the evening I went out with the gang from Comma Press for curry, quite a few Guinnesses, and a strawberry flavoured shisha outside a bar next to the main road at midnight with blankets over our knees. Later, while searching for places still open for a drink, we just missed the bar that was once the toilet where in 1952 Alan Turing was caught in flagrante with another man and then prosecuted (which Gordon Brown only just apologized for on behalf of the Government last month). Turing occurrence number three.

The fourth and final Turing-event was at Sackville Park, where there is a life-size statue of him sitting on a park bench holding an apple (he killed himself with an apple injected with cyanide) – which at 2am makes an uncanny, shit-scary silhouette.

I have the kind of mind that likes to think recurring motifs like that hold some kind of meaning, but after the three hours’ sleep I got last night, the computational part of my brain is kaput.