`Say nothing," David Woods's Donegal girlfriend told him when they found themselves in the middle of a riot in Derry. He used the phrase as the title of the unsettling play he developed with his comrade in Ridiculusmus, Jon Hough, which comes to Dublin for the first time this week. In it, the savagery of the expression "Whatever you say, say nothing" and the culture which surrounds it is ruthlessly explored. Woods and Hough have an endless and pointless conversation in the guises, mostly, of an English "peace worker" who has come to heal the Northern Troubles, and the Donegal landlady who shelters and exploits him when his world collapses: "I like to walk around, like the hills and the kind of rawness."

"You get plenty of that round here. Aye, very depressing."

"I find it very inspiring, actually, the rawness, you know?

"Very depressing, yes."

Hough and Woods are spacemen who came travelling to the North by pure chance and found, for a time, a residency at the Playhouse in Derry and then funding from the Arts Council of Northern Ireland. OK, they're not spacemen, they're English, but the experience of being based in the North since 1994 has confirmed, says Woods, his "alien status": "We're aliens everywhere we go . . . Even if you do try to settle, which we did in Derry, you'll be vomited out of the system . . .

"You get the charm offensive when you arrive. Then they realised we weren't tourists. They expect you to go back to where you belong - which in our case, would be Mars."

This parochial obsession with belonging fascinates Woods: "I used to go out with a girl from Dungloe (Co Donegal). I'd see people weaving this web of connections with her, and they they'd relax when they had her placed. Jon's name, Hough, rhymes with cough, but they'd convince themselves it was Haugh and then say, `I'm a Haugh as well, we must be relations', and try to weave the web . . ."

In fact, he found Derry and Donegal thickly Woods-ed; which prompted me to tell him my grandmother was a Woods from Donegal . . . Is this compulsion particular to Ireland? "I think I thought it was," he says. "But now I don't think it is, it's just heightened because of the conflict. Today, people are so insecure that you have this need for identity everywhere. It's really the source of all global conflict."

That's why Say Nothing is billed as being "about the peace process"; the long stone-walling masquerading as a conversation, which is the play, is making the point, says Woods, that while each side is saying "We've won!", "when they get to the nitty-gritty of making it work, it falls apart.

"If you really are interested in engaging with the other community, then you do it. It's a fear that has to be faced."

A bit like the deranged peace worker in Say Nothing, Ridiculusmus ended up running away to Donegal from Derry when things started to go rotten for them there; a death threat from the UVF was the least of it. They played the tourist-in-rural-Ireland experience for laughs, dressing up as American backpackers. Woods can't help cracking up: "Our accents were so bad, it was amazing we got away with it. But we were subjected to `The Blarney Parade', with people asking us, `What about a recitation, boys?' " He talks of the culture of the "turn", which causes the poor social worker to subject the landlady to an excruciating rendition of a ballad, until she begs him to stop.

Isn't "turns" the business Ridiculusmus is in too? Woods doesn't demur, but in fairness the element of compulsion is not there for the audience: "We're into interaction, not humiliation, but inviting them to play." The show that made their name was their version of Flann O'Brien's The Third Policeman, and the audience had a leading role: "We would induce the audience to bring bike lamps and parts along, and they could get a free "Kessler" (a long-dead brand of beer).

"Some people would bring their bikes in and we used them as sound effects. We even had motorbikes and cars . . ."

Woods and Hough had met at The Poor School, a drama school in London for people short of funds, staffed mostly by teachers "moonlighting" from RADA. It ran from 6 p.m. to midnight to allow students to work full-time and, in an O'Brien-esque turn in his life, Woods worked as a public finance accountant ("Is it a sedentary job in London?" he asked at his graduate careers fair.)

They hooked up with a ukelele player called Angus - "Actually, it was a banjulele, he was quite definite about that, I think he found it in a bin" - and did an "anti-comedy" show called The Tomato Club, in which they were pelted with tomatoes by the audience. Eventually, they were thrown out of the venue because of the mess. It was during the successful run of their version of Jerome K. Jerome's Three Men in a Boat that a copy of The Third Policeman was first proffered by someone working backstage.

Their Third Policeman became the meeting-place for The Third Policeman cult in London - one man came 28 times. They could have run forever, but instead they toured it to Ireland: "Everyone wanted it - from Glenveagh to Skibbereen - who wasn't a pretentious art snob from Dublin." Although they have toured as far as Adelaide, and have an invitation to play at the Sydney Opera House, the attitude in Dublin, he says, has been, "Who are these aliens playing our national god?", which makes the opportunity offered by this week's Theatre Symposium so tantalising.

Tonight's show, Yes, Yes, Yes, is inspired by a certain Y.M.M. Murphy, who is President of the International Humour Society in Bangalore: "They believe telling jokes is a spiritual pursuit," explains Woods, on the verge of giggles. "I'm in regular contact with him now, he's like the Indian Flann O'Brien." This show relates also to Woods's next project, with a Japanese singer called Kazuko Hohki - "of the Frank Chickens, they had hits like We Are Ninja - about her mother, who was the Comic Priestess in a Shinto cult called The House of Enlightenment, and would intone: `I am happy, I am healthy, let us laugh.' "

Another project for this summer is a site-specific work called Paranoid Household, which sees them living in a house in Wales for a month exploring "the problems of sharing space". It's a problem which he and Hough must be all too familiar: "It's like being married, really - it's unbearable. And we're not paly. But on stage, it's magic, and we'll run with it as long as it lasts. It's so intense you dread it, and that's why we have to do it. It's like people have to do the peace process."

Yes, Yes, Yes runs tonight at Players Theatre, TCD, at 6 p.m.; Say Nothing runs on Thursday at the Samuel Beckett Theatre at 8.30 p.m.