Alan Turing was a brilliant mathematician, computer scientist and cryptanalyst.

His work at Bletchley Park during World War Two is credited with having shortened the war by at least two years and saved the lives of 14 million people.

In 1954, at the age of just 41, Turing died of cyanide poisoning. The cyanide was probably taken deliberately, although this was never proven.

Alan Turing – Guilty of Love looks at Turing’s personal life and relationships, and asks why the world was so keen to judge and control a genius who simply wanted to be left alone to do his work and live his life. This man, who had done so much to serve his country, became a victim of a lethal cocktail; the paranoia of the Cold War mixed with the long-lasting legacy of Victorian bigotry.

Guilty of Love opens with Turing (Jamie Sheasby) rushing into a police station to report a crime. This crime and the chain of events it sets in action become the frame for the whole story, but for the moment we don’t know what it is.

Instead we’re swiftly transported to Sherborne School. Frances Morcom (Joanna Harte) is dropping her son Christopher (Andrew Hornyak) off at the start of a new term when Alan, the new boy, arrives. It’s the first day of the 1926 General Strike, so he’s simply run all the way from Southampton Docks. It’s a fateful meeting. Christopher has a telescope and enjoys breaking the school rules to go stargazing on the roof. Alan knows the exact distance between the earth and the cosmos, but he’s more interested in the inner workings of the telescope. He’s also interested in Christopher; they’re soon having illicit astronomical meetings – and guess which star they’re looking at? Venus of course.

Jamie Sheasby plays Alan as a rather earnest, intense person, one who can’t see the point in not calling a spade a spade, or for that matter a homosexual a homosexual. He’s either not aware of, or simply can’t be doing with, the numerous strange subtleties of post war social interaction. Sheasby’s posture and gestures exactly fit this personality. Turing may be vulnerable but he doesn’t realise it; he sees life in black and white and just does whatever to him seems the logical thing. Until, that is, he meets Christopher; then he’s up on that roof, breaking the rules in a most uncharacteristic fashion.

Guilty of Love is a musical, and the refrain of Venus in Daytime, Turing and Morcom’s first song together, highlights a motif which will run through the story; watching. The boys are watching Venus, and watching one another, the staff are watching them, and when they are discovered by the Headmaster he demands to know

‘Quis custodiet ipsos custodes? (Who watches the watchers?)’

before sentencing them both to 100 lines. And those lines aren’t just about climbing on the roof; the boys are told they must not

‘deviate from established rules…..and undermine the state.’

The singing of We are the Watchers in military style adds to the growing atmosphere of threat.

The scenes of the play are punctuated with the appearance of a guitarist who provides a kind of Biblical chorus to the action, singing about Jesus first recruiting his disciples at Galilee, and later praying in the Garden of Gethsemane before his betrayal and crucifixion. Although the play is obviously trying to draw parallels between Turing’s and Christ’s lives, this did seem a little far fetched to me.

When we return to the scene at the police station, we learn more about the crime – a burglary – that Turing wants to report. By explaining how he knows the identity of the burglar, Turing ends up getting himself into big trouble; again the script leaves us to decide if this is naivety on his part or a more deliberate disregard for the rules .

Meanwhile the rest of the cast chant the terms of the Criminal Law Amendment Act 1885, a terrible piece of legislation that Turing has either never heard of or doesn’t think relevant. But this is 1953 and homosexual acts between men will not be decriminalised in the UK for another 14 years; the gay world exists largely behind safely closed doors. Turing is out and if not proud then at least not bothered, and it’s hard to fathom precisely why this is the case. When his counsel asks him if he knows what prison will be like, he asks if he will be able to go running and do The Times crossword. In many ways he’s a typical 1950s Cambridge academic.

When asked by his defence counsel why he’s freely admitted to eight counts of Gross Indecency with Alan Murray, Turing’s reply further illustrates his somewhat unworldly approach to life;

‘Because you have to tell people the truth.’

And it is now that we learn that Christopher Morcom died at the age of just 18. His death has clearly devastated Turing. He’s protected himself by trying to avoid feeling anything ever again.

When his lawyer points out that there is a mysterious gap in Turing’s life history the action moves to Bletchley Park, where Turing was recruited to help the war effort by counteracting the operations of the Nazis’ cipher machine. Turing likes numbers, and describes ENIGMA as ‘beautiful’, a comment that doesn’t go down too well with his line manager…but he understands the need to crack the code, and eventually he does.

Everything at Bletchley was covered by the Official Secrets Act, which meant that after the war none of its employees could account for the years they spent there. Turing’s ‘excuse’ was that he had been declared unfit on health grounds.

We see the codebreaking team assemble for the first time; they seem quite a jolly lot, and there’s an entertaining song and dance routine, in which the men and women take turns to bob up and down in a pattern not a million miles away from Turing’s later explanation of binary code.

It’s at Bletchley that Turing meets Joan Clarke. Joan is clever; she and Turing have instant rapport over both crosswords but the content of Turing’s academic paper on computers, written while he was a Fellow of King’s College, Cambridge. Caitlin Downie does an excellent job as Joan, bringing out the character’s intelligence, kindness and bravery, but also her humanity; she may love numbers almost as much as Turing does, but she also yearns for poetry, something Turing’s machine can’t process. The pair go to the cinema (a lot, and always to see Snow White, the film with which Turing is weirdly obsessed) and on cycling holidays, they play chess, they even get engaged. Turing makes no secret of his homosexuality, but he wants to get married and have a family; Joan is totally on board with this arrangement.

In a touching scene, Turing takes Joan to visit the aging Frances Morcom, who’s still grief-stricken for Christopher, her golden boy. In sharp contrast to her happy banter with her son all those years ago at Sherborne, Harte now brings great dignity and pathos to the role of the bereaved mother. Over time she and Turing have become close; there’s clearly a deep bond between them, one founded on their shared love for Christopher and their shared misery at his loss.  With Mrs Morcom, Turing can express his true feelings; when he’s elsewhere he’s determined to show that

‘Man is a machine made up of intellect and obsolescent body parts.’

Is this what he really thinks, or what he would like to think?

Back in the court, Turing is offered a choice; prison or probation + a course of injections that will cause

‘a reduction of desire, a suppression of love’

Britain was at this time terrified that homosexual men with ‘sensitive’ information would either be blackmailed by enemy countries or would simply choose to follow Burgess and Maclean and defect to Moscow. If the 1885 Act (or at least the relevant part of it) had been repealed the blackmail problem would have gone with it, but in the 1950s this was apparently unthinkable.

The final emotional scenes of Guilty for Love imply something which does not seem to be reflected in the facts, but may be intended to work as metaphor. They’re certainly effective.

Guilty of Love tells the story of a man who, in the character’s own words

‘led a blameless life, free from crime save the one which dwells within and is quite uniquely mine…I am guilty of love.’

The play is well acted, though at times the singing seemed to put a strain on some voices (the cast are, however, almost at the end of a non-stop 23 day run.) I did feel that the recorded music sometimes drowned out the voices, but that may have been due to where I chose to sit – most people were much nearer the stage. All in all, Jane Bramwell and Michael Brand’s musical tells us a tragic story in a lively, perceptive and moving way.

Alan Turing was not officially pardoned until August 2014.

Over 60 countries worldwide still have laws that criminalise homosexuality; 29 of these are members of the Commonwealth. Many laws date from colonial times.

Alan Turing – Guilty of Love is at Hill Street Theatre (Alba Theatre), 19 Hill Street, at 2.10pm every day until 27 August.

The Turing Trust, a charity set up by Alan Turing’s great nephew in 2009, takes donations of unwanted computers (less than 6 years old), tablets, mobile phones, cameras, projectors and headphones and reconfigures them for use in schools in Africa. During Covid lockdowns it also provided equipment to UK schools whose pupils would not otherwise have had access to IT. Leaflets are available after the show, or you can find more information here.