It has been a summer of Sherlock Holmes at Cumbria’s theatres. After the hilarious three-hander The Hound of the Baskervilles at Theatre by the Lake, Sarah French feeds back on an even smaller cast in Watson: The Final Problem

Attracting ten million viewers at its peak it is not surprising that Tim Marriott, one of the stars of BBC leisure centre-based sitcom, The Brittas Empire, used to get recognised in the street.

His character, Gavin Featherly, was one half of the first openly gay couple on a primetime television sitcom. Based on the madcap goings on at Whitbury Newtown leisure centre under the exacting leadership of irrepressible manager Gordon Brittas, the show ran for six years from 1991.

Tim (back row, second left) as Gavin Featherly with the rest of the main cast of The Brittas Empire (c) BBCTim (back row, second left) as Gavin Featherly with the rest of the main cast of The Brittas Empire (c) BBC Tim had spent the previous decade as a jobbing theatre actor. Despite the success of The Brittas Empire – he appeared in every episode, and in an episode of Allo, Allo too – he says TV killed his career as “a serious actor” and he ended up leaving the business to go into education for the next 18 years, latterly as head of department in the independent sector.

He had, however, continued to write and when actors were twice unable to perform his solo play Shell Shock – an adaptation of Neil Watkin’s semi-biographical novel – he stepped into the breach returning to the stage after nearly two decades.

The play was a huge success winning awards and playing at Edinburgh Fringe, New York and Australia to audiences as diverse as serving soldiers, a sold-out 1,100 seat theatre on Queen Mary II and as pre-dinner entertainment.

All of this came to light in an after-show Q&A with Tim, having ditched his costume and a pot of English Lakes ice cream in hand, at The Old Laundry Theatre, in Bowness-in-Windermere, a few minutes from coming off stage in Watson: The Final Problem.

He penned and stars in the solo show and the follow-up chat shed fascinating light on how it came to be and the past life of the actor-turned-“writer who performs his own work”, as he puts it. Most of the full-house audience missed it, however, with only 20 or so of us staying back. Paraphrasing Tim, the rest of the audience may have had dinner reservations, been drawn to the bar or been “so bored with the play they didn’t want to hear any more”, but it is the beauty of small theatres like Old Laundry that this sort of intimate chat can be accommodated, and I’d always recommend staying if you can.

We learned his wife was helping with sound at Bowness and that he would love to revive The Brittas Empire, which has been talked about but is unlikely to happen.

We also heard how Watson: The Final Problem came into being after he was staying with friends at Meiringen, in Switzerland, where there is a museum dedicated to Sherlock Holmes and a bronze statue of the character in the square that is named after him, not to mention Sherlockerli sausages in the butchers and chocolates imprinted with his image at the village bakery.

Less than a mile from the village is the real Reichenbach waterfall, where fictional Holmes and his arch enemy Professor James Moriarty meet their end.

The play, co-written and directed by Bert Coules (BBC’s The Further Adventures of Sherlock Holmes; Cadfael; Rebus) with original music by Clive Whitburn, builds to this point. It begins, however, with Watson at home, alone and lonely.

After the loss of his beloved Mary and dear friend Holmes, and still suffering from his war wounds, Watson is a broken man vulnerable in a city that is rife with rumour, even admitting he has contemplated suicide.

He seeks solace and recovery in storytelling first filling us in on the time he qualified as a doctor then was despatched to India with the army. Having succumbed to Afghan bullets in the first Anglo-Afghan war, portrayed to dramatic effect with sound and lighting, he had gravitated back to the “great cesspool” of London.

He tells of how, through his old Barts Hospital friend Stamford, he met Holmes who was looking for someone to share rooms in Baker Street. Here, classical experiments and target practice take place in the living room. “It’s thanks to me you know these things,” reminds Watson, who is the narrator of all Sherlock Holmes’ adventures.

The Old Laundry Theatre, in Bowness-on-WindermereThe Old Laundry Theatre, in Bowness-on-Windermere

Moving around his parlour, where Mary stares out from a photograph, he shares details of well-known tales The Speckled Band, The Sign of Four and The Reichenbach Falls. Now in full swing, the resilient Watson recounts the story of how the duo tried to evade the “reptilian and repugnant, Napolean of criminals” Moriarty.

Watson recalls how Holmes had instructed him at the time to take an unconventional route to the station, finding his friend in disguise in the compartment, followed by a switch of trains and their race across Europe eventually reaching Switzerland.

There, the duo took a pleasant walk to see the falls only for Watson to be called back to attend a patient. It was, of course, a hoax and as realisation dawned that it was the work of Moriarty, by the time Watson returned he was too late to save Holmes, a regret the doctor has learned to live with.

The cosy setting, the warmth with which Tim plays Watson and the nature of storytelling could risk a slide into slumber. But the pace of Tim’s delivery, his movement around the set and the scenes cleverly triggered by sound and a change of lighting help bring the story to life and advance the plot – and provide cues for Tim in an impressive 60 minutes of monologue. He later reveals it took three months to learn, mostly reciting to his dog on walks.

One audience member later muses that plays with lots of action and characters can distract – “I never know where to look,” he says. Solo shows, on the other hand, provide clear focus for the audience, but even more pressure for the actor and the writer to grip the audience.

Tim clearly has affection for Dr Watson, who has sometimes been wrongly played as a dim, put-upon sidekick, which is not how Conan Doyle, a fellow doctor, intended. “I wanted to do the man justice,” says Tim.

At the end of the play when the doorbell rings, Watson prepares himself for his next adventure. Holmes had told Watson to “expect the unexpected” and, of course, the sleuth isn’t dead, having faked his own death to throw Moriarty off the scent.

In real life, Conan Doyle had killed off his famous fictional detective, but his fans and publisher demanded that he return, so he is given a second chance at life.

Much like Tim and his career in fact – and aren’t we all glad to see him back.

• In November at Old Laundry Theatre, A Dragon’s Tale (for children aged four-11) and Dad’s Army Radio Show, November 1; Robin Hood: The Pantomime, November 2; Hancock’s Half Hour, November 29. oldlaundrytheatre.co.uk.