Peter Crawleyon theatre thrown onto the street

So there I was, sitting in the Peacock Theatre last Friday, immersed in Big Love's playful flutter of action, politics, symbols and set pieces, and busily trying to interpret the fire alarm. What was director Selina Cartmell trying to say by drowning out a quiet dialogue with a piercing siren?

By the time I had a plausible reading - the alarm signified societal impediments to meaningful communication between genders; the instruction to evacuate represented a solipsistic retreat from sexual co-dependency - a stage manager explained that the fire alarm signified a fire alarm and the instruction to evacuate represented an instruction to evacuate. So much for semiotics.

It says a lot about an audience that once we buy into the fictive world of a play in progress, a ringing bell is only ever considered a false alarm. "Fire!" yells out Rosencrantz, apropos of very little, in Tom Stoppard's Rosencrantz and Guildenstern are Dead, before peeking out at the stalls in contempt. "Not a move," he says. "They should burn to death in their shoes."

At the Abbey, no one seemed unduly worried - the staff responded excellently, and besides, that theatre hasn't burned down for years. But something surreal happened outside when both the audiences and actors of Big Love and Three Sisters were disgorged into the street. It was like being woken too soon from a dream, dragging shards of broken fantasy into the evening light of the real world.

In fact, Lower Abbey Street wasn't looking very real at all. A valiant troop of 19th-century Russian infantrymen surged through the crowd carrying one of the Prozorov sisters to the safety of the Irish Life Centre. They narrowly avoided a gaggle of women in satin dressing gowns and bridal lingerie seeking refuge near the Salvation Army. Whole centuries and cultures collapsed and folded into one another and the city's credibility seemed to be under strain. Audience members offered words of encouragement: "It's going very well."

It really was. A few minutes later, this dreamlike piece of impromptu street performance was over and it struck me as a great shame that Hiberno- Russian-miserabilist-period drama is so rarely shuffled into post-modern-American-ancient-Greek-gender-political-theatre.

I don't know if this sort of thing should happen more often, and it must be horrible for actors to be interrupted, but it's nice to see what happens when reality and make-believe are desegregated. When Ciara O'Callaghan and Angus Óg McAnally returned to the stage with apologetic smiles ("wasn't that weird?"), we greeted them with effusive, heartfelt applause ("yes, it was!") as they slipped back into character. From there the company could do no wrong. The gap between audience and performers disappeared. It was our show now.

A real bond was forged with a false alarm, and it was this, rather than any flames, that finally brought the house down.