"We have got closer than ever before to a certain dream," says Tim Etchells.

"That of making a work which makes no sense whatsoever and yet functions effectively at every level."

Enter an over-aged cheerleader, a rampaging rock chick, a temperamental actress, two joyless clowns, two naked men carrying cardboard silver stars, some head-banging roadies and a nymphomaniac in a gorilla suit in what promises to be the most brilliantly chaotic show yet from Sheffield's Forced Entertainment.

An ensemble of six artists (expanded to ten for this 20th birthday production), Forced Entertainment formed in 1984 around director and writer Etchells.

Using theatre, durational performance, installations and digital media to get at the fragmented heart of contemporary urban life, they produce work which, in its dark intelligence, surreal comedy and unexpected logic, is best described as existential vaudeville. (Etchells, anything but pompous, prefers to refer to the productions as "mad spectacle things".)

Their first project, back in 1984, was Jessica In The Room Of Lights, which used taped voiceover, soundtrack and choreographed action to tell a blurred narrative about a cinema usherette whose real life became mixed with films.

Their last live performance piece, 2003's Marathon Lexicon, was a 12-hour lecture in the form of an A-to-Z.

Moving from accounts of "accidents" and "anti-climaxes" through to "trembling", "voyeurism" and "waiting", it used contributions from contemporary writers, thinkers and artists to create a live event which fell somewhere - or rather highlighted the similarities - between an endurance test and a panel presentation.

Other Forced Entertainment highlights include the Tate Modern performance 12am: Awake And Looking Down, in which silent performers reinvented themselves using cardboard signs and a pile of jumble sale clothes, and 1999's Who Can Sing A Song To Unfrighten Me?, a 24-hour carnival of kings, skeletons, zoo animals and ballerinas which stretched without a break from midnight to midnight.

But for those unfamiliar with their work, Bloody Mess, weighing in at a relatively flippant two-and-a-half hours, is the perfect place to start.

Beginning with a slapstick scene between two scowling clowns who row over the placement of chairs for the oncoming actors, it goes on to encompass everything from popcorn throwing to a lecture on the Big Bang.

Disguising its wisdom beneath foil ribbons and strobe lights, Bloody Mess promises to be a gaudy pop art party with a capricious desire to make you stare into the void.

"In this work it's the live moments which really matter," Etchells observes. "The moments in which the viewer has to join the dots and fill the gaps. We say it has a beginning, a muddle and an end."

Starts 8pm, Tickets £11/£9, Call 01273 685861