Akram Khan is at an interesting point in his career. The 50-year-old dancer seems to have had endless “final” performances – and it is four years since he has been seen on stage in the UK – but, of course, he is not going to stop dancing. A dancer is simply who he is. Anyone can see that. It is in the way he rips through the air, a powerful storm that magically leaves no damage in its wake; it is in his killer reflexes and rich lyricism, his whirling arms and spins, his movement now a little less about textbook exactitude, more about grabbing the moment and dancing with it. But for all his main character energy, Gigenis is not really about Khan, far from it. He has gathered an ensemble of Indian classical dancers, all expert in their fields: bharatanatyam artists Mavin Khoo, Mythili Prakash, Vijna Vasudevan and Renjith Babu, young Odissi dancer Sirikalyani Adkoli, and Kapila Venu, who practises Kutiyattam, one of the oldest theatre traditions in the world. After more than two decades exploring the meshing of his own specialism, kathak, with contemporary dance, ballet and flamenco, Gigenis is a return to Khan’s Indian classical roots, his ode to tradition. These are storytelling forms, and Gigenis is loosely based on the Mahabharata (Peter Brook’s production of which Khan appeared in, aged 13): there is a mother, two sons on different paths, war and a death. But most thrilling are the dance passages with the whole group in mesmerising unison, urgently partnering some exhilarating music that is devised and performed by seven musicians lining the sides of the stage, with a big round copper drum, the mizhavu, at the back. There is no set but there is atmospheric lighting, and an often sombre feel with regular rumbles of thunder (or something worse). There is a sense of foreboding about the world that echoes through the centuries, connecting the ancient and the present. Of the dancers, Venu is startling. In her opening solo she appears transfigured, eyes wide with glinting whites, her small frame expanded by her sheer presence, wing-like arms sweeping her into the air. Vasudevan and Babu portray a couple emanating an aura of goodness, the warm beating heart of their connection thrums so you can feel it (they are a real couple, but that doesn’t always translate on stage). The fine details are beautiful, the dancers’ hands a world in themselves, Prakash’s fingers flickering at 24 frames a second like licking flames. There is brief, not hugely illuminating text (Khan’s usual impressionistic way with dramaturgy) and, especially without expert knowledge of these forms, it is unlikely you would understand every subtlety of gesture. But they are all deeply convincing in their worlds and it is engrossing even if you don’t get the meaning. In a nice line in the programme, Khan says that, in the modern world, we need to “see it in order to believe it”, while for Khan’s grandparents it was the other way round, “we must believe in it in order to see it”. You believe in these dancers. At Sadler’s Wells, London, until 24 November