Behind-the-scenes look at Doctor Who. The Doctor has a new companion, Martha Jones. By sheer courage and determination, she has wowed the Time Lord and been offered a place on board the Tardis. Featuring exclusive footage from the third series and interviews with Freema Agyeman, who plays Martha, David Tennant and head writer Russell T Davies, the programme examines the development of Martha's character and the huge interest behind the casting of the new companion.