A Disappearing Number - TNT

This is a story about passion, about the love of a man and a woman, about a friendship based on a mutual academic interest, and, above all, about the unexpected beauty of pure mathematics. An evening at the theatre which begins with a maths lecture may not sound very promising, but in the ingenious hands of Simon McBurney and his company, Complicite, it develops into something mesmerising, moving and profoundly beautiful. Interweaving a contemporary fictional love story (Saskia Reeves oozes intellectual enthusiasm as a dowdy academic who comes alive in front of a whiteboard and captivates an American-based futures dealer) with the First World War collaboration between the mainly self-taught Brahmin genius Srinivasa Ramanujan and Cambridge don G.H. Hardy, McBurney creates a high-tech, multilayered exploration of infinity, morality and cross-cultural connections. The result delights the eye, pleases the ear and stretches the expectations of conventional theatre. Not to be missed. Barbican, Silk St, EC2 (0845-120 7550). Until October 6. £10-£40