In a crowded basement in the heart of London theaterland, Richard Vranch is directing an exhilarating performance of "Nelson and the Cheese Grater."
It's a surreal tale, full of historical adventure, nautical ribaldry, and formidable quantities of mature brie.
Not heard of it? It's hardly surprising, as the improv piece was invented by the five performers on the spur of the moment.
But the genre will be familiar. It's grown from unpromising beginnings in the unlit, seamy corners of the performing-arts scene to center stage at scores of mainstream venues across Britain.
And now, with its top stars eyeing America and other overseas markets and its audiences more numerous and knowledgeable than ever before, live comedy can truly claim to be one of Britain's fastest-growing forms of entertainment.
More than 150 clubs have sprung up across the country, the majority over the past decade. One chain of clubs, Jongleurs, claims to be the largest in the world, with 17 venues and 2 million patrons each year.
"London is the comedy capital of the world," says Mr. Vranch, a veteran of the British live scene with almost 20 years of performing with the Comedy Store Players, a group of improvisers based at London's Comedy Store. "We've got 50 or 60 clubs here, compared to the dozen or so in New York."
"The audiences are growing and getting more sophisticated and more demanding, and that means you have to work hard to keep up," adds Vranch after a night of hilarity whose particular high points were an improvised imitation of a Moldovan goatherd and an intergalactic musical entitled "Bum Cheek 9." "It keeps it edgy."
But is it edgy enough to export? That is the big question facing Britain's burgeoning roster of comedians.
The success of stand-ups such as Eddie Izzard in America, and the recent triumph of Ricky Gervais and his tragicomic "The Office" at the US Golden Globes last month has set many wondering whether the British scene is about to go international.
But can clipped consonants and even more clipped irony find an audience in farther-flung places? Places where people might not know who Lord Nelson was (a British admiral), or what a cheese-grater is for?
"You'd be surprised," says Vranch, who was taking performers on a tour of India for a series of improv nights. "They like us in China as well [because of] the TV series 'Whose Line Is It Anyway?' "
Arnold Engelman thinks the US scene is ripe for a British invasion. The New York-based producer and president of WestBeth Entertainment is bringing over a team of British comedians for a festival next month at the Village Gate Theater.
Mr. Engelman, who has already promoted Izzard in the US, says that British humor has "gone down incredibly well" in America.
"Stand-up comedy in England is a creative art form," he says. "It's on at the West End in the same way that a Shaw play or a musical is on."
In some ways, the cultural barrier is less of a problem, having been eroded by the prolific exchange of television programming in recent years. But Engelman cautions that not every British funnyman will make it big stateside. He says WestBeth have been very specific with the comedians they have chosen - talents like Omid Djalili, Boothby Graffoe, Bill Bailey - to ensure universal appeal.
"I don't think every British comedian can come over here and do well," he says. "The comedians we are choosing - their humor has universal appeal not necessarily tied to specific nationality."
A British comedy invasion of America would certainly be something to smile about. As comedy journalist William Cook wryly notes, the last British stand-up to become a superstar in America was Bob Hope.
Since then, it has mostly been one-way traffic - on the stand-up front, at least - with North American comedians a regular feature of the British comedy arena.
Mike Myers was a founder member of the Comedy Store Players, and Greg Proops is a regular at the club; Rich Hall has said he prefers the British scene to America; Bill Hicks was possibly better understood in Britain.
And it's not just the comedians that Britain gets from across the Atlantic.
Don Ward, founder of the Comedy Store, Britain's first dedicated comedy club, says that he got the original idea for the 'comedy room' following a trip to America in 1978, when he witnessed provocative acts performing original, observational material that "had a go at the establishment."
"In 1979, there was nothing like that here," he recalls. "We spawned an entire industry." Early shows were anarchic, dark, and controversial, but as Mr. Ward says, the spectacle of punters shinning up drainpipes to get into his packed venue proved that he was onto something.
"There were queues right around Soho, so I put in an earlier show," he says. "We gradually added other nights during the week, and eventually moved to a bigger place in 1984."
Britain, it turned out, was fertile soil for comedy nights. The nation's wry, sometimes ribald, sense of humor was long evident on film and television. Now the live scene was about to take off.
"In a way, it's a throwback to the music hall of 100 years ago, where people would go out and have drink and food and there would be a show and the basis for the show would be comedy and music," says Ward. "Now, music hall is coming back alive again with the comedy rooms."
The Comedy Store itself grew from a dingy, chaotic 100-seater to a hugely popular 400-capacity club with two sister operations in Manchester and Leeds. Ward says there are plans to open new venues in at least four other cities.
Maria Kempinska, who founded the Jongleurs club 21 years ago, is also reporting booming business, having boosted her number of outlets from eight in 2000 to 17 today.
"We've got 2 million people a year going in," she says. "It's a very profitable business."
Jongleurs alone employs 600 comedians at its venues, and there is never a shortage on talent.
A recent call found 250 volunteers lining up to showcase their material in competition. Young Britons, it seems, no longer aspire exclusively to rock stardom.
"They all want to be Ricky Gervais or Peter Kay," says Mr Ward, mentioning two of Britain's foremost funnymen of the moment.
Comedians are the new celebrities in Britain. Successful performers are ubiquitous, enviable and fascinating, gossip fodder for the tabloids, prime targets for advertisers and moviemakers. Some have their own newspaper columns, others their own TV quiz shows or radio programs, or bestselling books.
And comedy nights are rapidly consolidating their status as one of the most popular ways to spend an evening.
"It's close-up, you feel the interaction, it's quite risky, you really don't know what's going to happen, it's not scripted, and it makes you laugh," says Kempinska. "It's a very exciting medium."