WELCOME to a new Sherlock Holmes story, as told by The Flanagan Collective, the York company best known for their boutique musical plays.

Like Some Small Love Story, Beulah and Babylon, the script will be written by Coxwold playwright Alexander Wright, but Sherlock Holmes: A Working Hypothesis will not be a musical.

Instead of adapting an existing Sherlock Holmes story, Wright has drawn on elements of Sir Arthur Conan Doyle’s works to develop a new theatrical adventure set in 1963. "We join Sherlock three years after the Reichenbach Falls, posing as a Professor of Criminology, giving a lecture on himself, the great detective and master of deduction," says Alexander. "Presumed dead by his closest friend Dr John Watson, the pair quickly reunite and hurtle headlong into a new mystery. Their arch-nemesis, Moriarty, is at large and ready for one final battle."

The show will be the Flanagan Collective's most ambitious to date: an interactive, adventurous stage adaptation of Britain’s greatest detective stories, that will be staged in the Council Chamber of York Guildhall from August 11 to September 21 before taking to the roads on tour.

"Our version of Sherlock Holmes is about friendship and companionship, it’s about bringing people together to fix something rather than relying on other people and, of course, it’s about a good old mystery and adventure.There'll be riddles to solve, games to play and a treasure hunt, and the show also has a damn big sword fight and a free glass of wine, as well as opening up a space that’s not often used for theatre performances and that many people won’t have had the privilege of experiencing."

Dominic J Allen, such a wonderfully inventive, improvisational actor in his work in York with Belt Up Theatre and The Flanagan Collective, will play Holmes; George Williams, from Bristol interactive company Fine Chisel, will play Dr Watson, and Moriarty....?

"He's a secret," says Alexander. "Our narrative is that Sherlock has never met Moriarty because Moriarty sent an agent to kill Holmes at the Reichenbach Falls. Sherlock has arranged to give a lecture on the workings of Sherlock Holmes, but posing as a professor of criminology , in the hope that Moriarty will turn up, and then figure out which one Moriarty is in the audience, but Moriarty has already guessed this plan, but Sherlock doesn't know that yet!"

You can sense the enjoyment Alexander has had in creating such a story. "The play takes a lot of Sherlock Holmes as read, right up to the Reichenbach Falls, and then we leap off in a new direction, bringing together this new meeting of Sherlock Holmes, posing as a professor; Dr Watson, who thinks he's dead; and the 'secret' Moriarty."

Wright's Sherlock story comes in the wake of the Guy Ritchie films, starring Robert Downey Jr, and the BBC series with Benedict Cumberbatch. "And Ian McKellen is now doing a Sherlock Holmes story where Sherlock is 93 and coming out of retirement to do one last case, so it's really interesting that Sherlock still has massive appeal," says Alexander.

"I've now read every Sherlock Holmes book, and why I find Sherlock fascinating is that though it's such a well-known story and he's such a well-known character, doing a theatre piece about Sherlock is all about bringing people together and having a good and meaningful time.

"Although the Guy Ritchie films are escapist, they're not fanciful; they're popular, but they're not make-believe; they're saying, actually I wish someone could solve this situation. We spend a lot of time, whether it's Marvel comics or Benedict Cumberbatch's Sherlock, seeking someone to solve problems, so that's why I describe A Working Hypothesis as a play about superheroes and heroes.

"So hopefully, if we've done it well enough, Watson will come out as the hero, because Moriarty and Holmes are too caught up in a battle of wits. Watson comes out as the one saying, 'What matters more than your stupid games is that I get home tonight and everyone else here gets home', which makes him the everyman hero."

The Flanagan Collective and Hartshorn-Hook Productions, in association with York Theatre Royal, present Sherlock Holmes: A Working Hypothesis at the York Guildhall Council Chamber, St Helen's Square, York, from August 11 to September 21. Box office: 01904 623568 or at yorktheatreroyal.co.uk. Advisory age limit: ten plus.