A Disappearing Number takes as its starting point the story of one of the most mysterious and romantic mathematical collaborations of all time. Simultaneously a narrative and an enquiry, the production crosses three continents and several histories, to weave a provocative theatrical pattern about our relentless compulsion to understand. A man mourns the loss of his lover, a mathematician mourns her own fate. A businessman travels from Los Angeles to Chennai pursuing the future; a physicist in CERN looks for it too. The mathematician GHHardy seeks to comprehend the ideas of the genius Srinivasa Ramanujan in the chilly English surroundings of Cambridge during the First World War. Ramanujan looks to create some of the most complex mathematical patterns of all time. Threaded through this pattern of stories and ideas are questions. About mathematics and beauty; imagination and the nature of infinity; about what is continuous and what permanent; how we are attached to the past and how we affect the future; how we create and how we love.