Martha Jones is a fictional character played by Freema Agyeman in the long-running British science fiction television series Doctor Who and its spin-off series, Torchwood. Notably Doctor Who's first black female companion, she was introduced in the third series as a companion of the Tenth Doctor. According to the character's creator Russell T Davies in his non-fiction book Doctor Who: The Writer's Tale, Martha was developed from the beginning with the intention of appearing for the whole of the 2007 series, and to make guest appearances in subsequent series and crossover appearances in the show's two spin-offs; Martha subsequently made guest appearances in Torchwood series two and in Doctor Who series four in 2008 and special episode "The End of Time" in 2010. Martha was also intended to make guest appearances in the 2009 series of Torchwood and The Sarah Jane Adventures, but could not due to the actress's other work commitments.