"We can't see the audience from the stage," says Philip Franks, "but we can sense the complete stillness. It's as satisfying to an actor as gales of laughter."

Following a twice-extended West End run, Franks is currently reprising his lead role in this touring version of Journey's End, a 75th Anniversary production of RC Sherriff's harrowing play about British soldiers fighting in the First World War. And, he says, "doing this play eight shows a week for 12 weeks, it does get to you."

Written ten years after the armistice and based on the playwright's own experiences on the front line, Journey's End is set in 1918, in the British trenches at St Quentin.

In advance of the long-awaited German offensive - a day that saw the deaths of 38,000 men - a company of officers is preparing for the raid across No Man's Land in the knowledge that few of them are likely to survive.

With that rare, gentle intelligence which he has brought to all his parts, from The Darling Buds Of May and Heartbeat to classic TV adaptations such as Bleak House and even his regular appearances on Countdown, Franks plays Lieutenant Osbourne, the lynchpin of the company.

"Osbourne is the oldest," Franks explains, "and they all call him 'uncle'. My character used to be a teacher and he's good, decent, kind, an endlessly humane and sympathetic presence in the hell of the dug-out."

Osbourne reins in the manic Captain Stanhope (Tom Wisdom, better known as Coronation Street hairdresser Tom Ferguson), a "golden boy" and courageous commander who has taken to drowning his nerves in whiskey.

And he welcomes and reassures newcomer 2nd Lieutenant Raleigh (Richard Glave), a boy fresh out of school with his head full of glory and rugger, who still idolises Stanhope. But, says Franks, "how he copes with fear when he's alone is another matter."

Directed by Brighton's David Grindley, whose previous credits include Abigail's Party, a huge success at this venue earlier in the year, Journey's End uses the simple staging of a low-lit trench, with the taut script focusing on the emotional see-sawing of its inhabitants, from jokey camaraderie to desperate aggression.

"Journey's End is a set book and we get a lot of school parties," says Franks. "Before we start it's like a bear pit out there. Then we begin and suddenly there's this uncanny silence. One of the soldiers has just left school - it could be one of them. When the lights go up at the end, we can see the tissues and the tears."

Starts: 7.45pm and 2.30pm Thurs, Sat matinees, Tickets: £16-£24. Tel: 08700 606650