Alain Platel / Les Ballets C de la B, Sadler's Wells, London, review: It feels punishingly long, particularly in its scenes of turmoil

Dancers from Platel's contemporary ensemble les ballets C de la B perform the dark 'Nicht Schlafen' with music inspired by Gustav Mahler

The performers are utterly committed, with unison dances, stark poses and tightly drilled steps (Chris Van der Burght)

Death looms over les ballets C de la B's Nicht Schlafen, directed by Alain Platel. A hyper-realistic sculpture of three dead horses sits in the middle of Berlinde de Bruyckere's set, bodies piled up in a tangle of stiff limbs. Around them, the performers fight, scream and sing, moving into danced or musical harmony before falling back into chaos.

Founded by Platel in 1984, this influential Belgian theatre collective has a distinctive blend of extreme physicality with music and an eye to world events. The steps are often brutal, with performers often dragged about or painfully manipulated. The dance theatre choreographer Pina Bausch is an obvious influence, but Platel is much less interested in the personal: his power plays tend to be symbolic rather than individual. The company's strength is its directness of performance. It's also given to long, long stretches of messy angst.

The starting point for Nicht Schlafen was the music of Gustav Mahler. It's played in brief snatches here, fading in and out, while composer Steve Prengels adds sequences of cowbells and animal noises. The onstage performers also sing African polyphonic chants and part of a Bach cantata. There's an implied parallel between the tensions of Mahler's time, leading up to the First World War, and those of today.

Early on, the nine performers erupt in violence, attacking each other, tearing off clothes until everyone is left dressed in ragged tatters. They wander the stage as if lost, or tangle themselves into struggling, highly acrobatic knots. The music comes and goes around them. They ignore it, or let themselves fall into unison dances, stark poses and tightly drilled steps. One man climbs up another to perch on his shoulders. The only woman clambers over two men, held between them as she arches herself into tighter and bendier poses. Moments of apparent harmony get disrupted again.

The performers are utterly committed, especially when they sing. Boule Mpanya and Russell Tshiebua lead a polyphonic chant, drawing the other dancers into a shuffling, skipping dance full of lively rhythms. Then it's back to more confusion.

Like many C de la B productions, Nicht Schlafen feels punishingly long, particularly in its scenes of turmoil. The dancers flail and flail until it becomes dull to watch. The focus on disaster starts to feel self- indulgent, a limited view of the world's horrors.