Dance: Entity, Sadler's Wells, London

Two men are dancing, lifting each other, snaking in and out of knotty choreography. Behind them, a third walks on to the stage. He doesn't join the others, but a duet has already become a trio: you're aware of him, of a new pattern, of echoes between duet and soloist. One step, and the whole stage picture changes.

Wayne McGregor's Entity is full of transformations. Tangling group dances suddenly separate into serene partnerships, then splinter into solo dances. The choreography doesn't give these dancers obvious characters or emotions, but a backwards glance can still affect a whole sequence.

Entity is McGregor's first production for his own company in two years. In the meantime, he's worked everywhere from La Scala to the Paris Opéra Ballet, besides becoming the resident choreographer at the Royal Ballet. Returning to Random, he has renamed it Wayne McGregor / Random Dance. The company itself has changed: of these 10 dancers, seven are new.

In this new incarnation, Random is sleeker than ever. Many of these dancers have a ballet background. All are smooth and taut, while keeping up with McGregor's demand for flexibility and complex articulation. Torsos arch away from thrust hips, then wriggle so that bottoms jut out.

McGregor still has a taste for weird and unconventional moves. Feet are not just turned in but splayed and curled. Some positions are close to ugliness, but the brutality of earlier McGregor works has gone. Bodies coil rather than wrenching. The dancers go flat out, but they still have time for phrasing.

Entity, which will tour the world after this Sadler's Wells premiere, is billed as a diptych. The first half has music by Joby Talbot (of The Divine Comedy and The League of Gentlemen fame), with looping string lines played by the Navarra Quartet. The second half, by Massive Attack collaborator Jon Hopkins, uses percussive electronica.

Patrick Burnier's design frames the stage with three long panels, raised and lowered by counterweights. Film images by Ravi Deprees – a running greyhound, flickering static – are sometimes projected on to them. They're vaguely atmospheric, but add little to the performance.

Burnier's costumes are simple: black underwear and white T-shirts for men and women. The T-shirt markings are the dancers' own DNA codes. Lucy Carter's lighting design is dramatic but never murky; even in shadow, the performance stays clear.

The DNA codes are decoration, but they link to one of McGregor's themes. He's fascinated with science. Like several earlier works, Entity draws on McGregor's ongoing collaboration with scientists, including those involved in cognitive science, software development and neuroscience. Other works have put heart imaging on stage; Entity is pure dance with a scientific background.

The break between composers comes as a surprise. Right at the last minute, the dancers bounce into a final tableau. They only just get there in time, yet it's a calm image. The women sit, the men stand, all with one arm raised. There's an echo of the start of Balanchine's Serenade, with its shared corps gesture – but this is both a beginning and a middle.

It is an episodic piece, quite apart from the change in music. There's some padding, with churning group scenes that go on too long, particularly in partnered work full of clambering lifts. Entity sometimes loses focus, blurring into repetition.

Where McGregor is strongest is the full-bodied movement he gets from these dancers, and the fine use of stage space. He moves large and small groups against each other, or leaves single dancers in isolation. One strange moment has a dance in the foreground, while a couple wait behind them. He lies full length, his head pillowed in her lap. The background could be a narrative fragment, something from a story; the foreground is pure dance, fast and furious.

Tour dates from www.randomdance.org