1791 and the Doctor and Rose get to meet one of the most enigmatic, thrilling and important people in history: The Chevalier d'Eon.She used to be known as a spy, but then she used to be known as a lot of things.If there's one thing the Doctor knows it's that identity is what you make it.Choose a life for yourself and be proud. Mind you, if the Consortium of the Obsidian Asp get their way, all lives may soon be over.David Tennant's return to the role of the hugely popular Tenth Doctor has been huge news both times it's happened for Big Finish - with news of his teaming up with Billie Piper making newspapers when it was announced.Billie Piper, famed British actor of stage and screen, and companion Rose Tyler, reprises the role for the first time since her departure in the tear-jerking Journey's End Doctor Who story on BBC1.Guest star Nickolas Grace is familiar to a legion of fans as the villainous Sheriff of Nottingham in cult TV classic Robin of Sherwood.CAST: David Tennant(The Doctor), Billie Piper (Rose Tyler), Nickolas Grace (Chevalier D'Eon), Mark Elstob (Joxer / Butler), Tam Williams(Christopher Dalliard), Lucy Briggs-Owen (Hempel / Dance / Duchess), James Joyce (Darcy / Groom).