Tomorrow's pageant through Dublin includes 600 students who will bring chaos theory to life, writes Louise Holden.

In an otherwise tranquil square inch of sky, a tiny butterfly twitches. He upsets some neighbouring molecules and sends a shudder through the atmosphere. Other winged creatures feel the tremble and respond in their legions, whipping up a cacophony of wing beats.

The phenomenon attracts the interest of a scientist. He spreads the word among his scientific brethren and the maddest among them panic at the butterflies' odd behaviour. An experiment designed to placate the insects backfires, sending further disturbed waves through the atmosphere, upsetting the planet's natural balance and turning the world on its head. A frenzied media mob records the mayhem.

This is the outlandish tale that 600 transition-year students intend to play out at this year's St Patrick's Day parade through central Dublin. Theirs is far and away the largest part of the festival, accounting for a third of the entire parade. Each of the 600 students will be dressed in one of many costumes, from butterflies to mad professors. The story of the undoing of the earth from a butterfly wing to destruction will be told in a series of raucous choreographies performed around enormous floats.

The Nutterfly Effect was created in response to a call from the St Patrick's Day parade committee for a theme of mischief, madness and mayhem. Twelve schools have worked on the design and production of the story. The project is part of the Brighter Futures project for transition year, established by St Patrick's Festival in 2000.

Norma Leen of the festival is delighted with the way this year's students have interpreted the brief. "There is so much going on in this year's creation. Alongside the central theme of The Nutterfly Effect, there are swarms of butterfly catchers creating a storm of activity that sends DNA spiralling to the beat as DJ Mayhem spins the decks and the 'madness mob' follows. A character called Miss Chief, helped by her cotton-bud-wielding henchman, cleans all sensible thoughts from our minds. The 'Dali Darlings' let us view the world through their melting picture frames - a world turned upside down. The whole thing is just bursting with great ideas."

Muirne Bloomer, artistic director of this year's project, comes from the Irish dance company CoisCéim; she has helped all 600 students to find their inner dancers in time for the St Patrick's Day celebrations. She claims the hype has been enough to draw more timid students out of their shells. "More than 5,000 young people have taken part in the festival since Brighter Futures was established, in 2000. The whole project has to go from the drawing board to the street so fast that there's not much time for shyness. These 600 transition-year students responded really well to the theme of mischief, madness and mayhem. It has been a wonderfully collaborative process for all of us."

Lead designer Vanessa Daws, formerly of Macnas, has created a staggering number of incredible costumes based on the students' suggestions and drawings. "We gave them the themes, and they gave us back their ideas."

The students have been building their costumes in school for the past few weeks, and now all the costumes are awaiting their debut in the Digital Hub warehouse, on Thomas Street. It's an eerie sight: row upon row of doll-head helmets, fish on bicycles, Dali-esque melting imagery and hundreds of giant gossamer butterfly wings, poised for flight. Huge molecular structures rest against the back wall, ready to be whipped into a frenzy on the streets of Dublin.

The object of Brighter Horizons is not simply to get more bodies for the parade. Each year a new team of working artists, dramatists and choreographers is unleashed on willing schools to bring the creativity and design talent of students to a wider audience. By working with professionals, the students learn new skills, such as dance, performance, sculpture and design. The creation of an impressive pageant involves working with a range of materials and draws on skills from needlework to carpentry.

"The students are learning some of the basic tenets of design," says Bloomer. "They have brought their own storyboards to life. They have not shied away from any aspect of the project, because they created it. The guys are as enthusiastic as the girls, even when it comes to dancing. I admit I was surprised to find that one of the boys' schools displayed the most skill and enthusiasm when it came to choreography and dance."

St Patrick's Festival has teamed up with the Diageo Liberties Learning Initiative, at the Digital Hub, to document the Brighter Futures project, and two students from every school are attending digital-technology seminars. They have learned how to photograph, film and edit the Brighter Futures project. They will use their new skills to produce a short film for each school while Dublin City Council deals with the post-party mayhem and mischief that is the essence of St Patrick's Day.

This year's participating schools are: St Paul's, Greenhills; Coláiste Bríde, Clondalkin; Loreto College, Crumlin; St Joseph's College, Lucan; St Joseph's College, Stanhope Street; Coláiste De hÍde; Coláiste Dhúlaigh; Ballymun Senior Comprehensive; Notre Dame; Our Lady's School, Terenure; Coláiste Íosagáin and Oatlands College.

If you are interesting in seeing the students' work, haul yourself out of bed in time for the parade this year!