Imagine you’ve come to one of those post-industrial arts spaces like Glasgow’s Tramway or London’s Tate Modern. Imagine, though, this one is in the middle of a forest, the Bois de Vincennes on the outskirts of Paris. Then imagine the woman showing you to your seats is not just any old usher, but Ariane Mnouchkine, artistic director of Théâtre du Soleil. Hers is a name whispered in theatre circles with the same reverence afforded Peter Brook, Peter Stein and Robert Lepage, none of whom, to my knowledge, make a habit of tearing your tickets.

Not only that, but here in the Cartoucherie, a former army munitions warehouse, the actors are the same people preparing and serving the interval food. They’re still in their make-up as they dish out the aubergine salad. They make their own props and, before the show, you can see them in the wings doing their warm-up exercises. These are not the elusive gods of the West End stage, but people like you and me, visible, accessible, one of us.

It is in this atmosphere of community, collective effort and honest communication that 73-year-old Mnouchkine creates her astonishing productions. On one hand, they are actor-centred, built on the resourcefulness of her large ensemble. On the other hand, they are epic in scope, telling stories of long journeys and great quests. That was true, for example, of Le Dernier Caravansérail, a collage of real-life stories told by refugees from around the world. And it is true of Les Naufragés du Fol Espoir (Aurores), the tale of a group of European exiles voyaging to the southern hemisphere to make a new life for themselves.

It is the latter – loosely based on a posthumously published novel by Jules Verne – that will play in the specially adapted three-theatre space in the Royal Highland Centre at Ingliston, running back to back with Grzegorz Jarzyna’s 2008: Macbeth and Christoph Marthaler’s Meine faire Dame: ein Sprachlabor (an oddball music-theatre deconstruction of My Fair Lady). The set for Les Naufragés du Fol Espoir (Aurores) is being reproduced exactly as it is in the Cartoucherie, right down to the walls, and will take 15 containers to transport.

Serge Nicolaï is one of the show’s stars, if ‘star’ is not too gauche a word for this egalitarian company. It says a lot about the kind of fully-rounded artists with whom Mnouchkine collaborates that Nicolaï is a whole lot more than just an actor. On this show, translated as The Castaways of the Mad Hope (Sunrises), he is also the designer and part of the script-writing team. When I speak to him, he’s in the middle of directing a production of Sartre’s No Exit in Buenos Aires. Like his fellow performers, he is as much a creator of this four-hour show as director Mnouchkine or writer Hélène Cixous. ‘It’s my job to be an actor and to make the set,’ he says. ‘It’s industry. It’s a factory of theatre. There is no star system. Because it’s a collective creation, it is always talking about groups, the story of people, not three or four people, but many.’

In a company where actors are on the same salary regardless of experience, Mnouchkine focuses the group’s creativity by suggesting a starting point and, over a lengthy rehearsal and improvisation process, shaping the work as it emerges. ‘The genius of Ariane is that sometimes I think she knows everything from the beginning,’ says Nicolaï. ‘We improvised every day for almost one year. She is the eye, receiving everything we’re doing and managing it. She’s like the conductor of an orchestra. At the beginning, she is like a blank sheet of paper, saying, “ok, let’s go to work and see what happens”. She is absolutely open and, at the end, she keeps what is absolutely necessary for the story.’

Set in July 1914, that story follows the journey of the Fol Espoir passengers who want to set up a community in Cape Hope while the rest of the world hurtles towards war. In this production, we watch a film crew attempting to tell this tale of thwarted idealism using restaurant staff as actors. ‘This is the story of a group of people who are trying to do something almost anarchic in the original sense of the word,’ Nicolaï adds. ‘They are all pacifists. This is something they need to do as a way of fighting against the war which is growing in Europe. It’s a big story of politics and the last possibility of freedom in the world, for socialism.’

In Mnouchkine’s theatre, the grand communal themes she explores on stage are consistent with the way she treats the audience. These are plays about society for society. Because of that, the audience must play its part. ‘The public all the time need to be educated,’ says Nicolaï. ‘It’s necessary not to enter the theatre with all the baggage of the day. Even in Paris, we are not in the centre, we are in the wood; you don’t have the Metro, you have to take the bus and then you have to find the theatre. It is a crusade for people. When you get your ticket, there are no numbers; to get the best place, you have to be the first one. The show starts with Ariane at the entrance. We open the theatre one hour before and Ariane almost all the time opens the theatre.’

The four-hour running time of Les Naufragés du Fol Espoir (Aurores) is part of the same philosophy even if, in Mnouchkine’s hands, the hours fly by. ‘In our society, time passes so quickly,’ says Nicolaï. ‘But we can’t make theatre with speed. It’s not graffiti sprayed quickly on a wall. It’s not fast-food art. Four hours is a short show for Théâtre du Soleil. For us it’s very easy. You’re lucky it’s not eight.’

Les Naufragés du Fol Espoir (Aurores), Lowland Hall, Royal Highland Centre, 0131 473 2000, 23–28 Aug (not 26), 6pm, £30–£35.

Les Naufragés du Fol Espoir (Aurores) / The Castaways of the Fol Espoir (Sunrises)