Udham Singh, legendary in India but barely known in the western world, was present when the Jallianwala Bagh massacre in Amritsar was perpetrated. Legend has it he picked a clump of bloody soil and swore to avenge the massacre. Twenty-one years later, he walked into Caxton Hall in order to shoot Michael O'Dwyer, who was one of two men behind the murders. Dan talks to Anita Anand, who tells this compelling story in full.