About Doctor Who Season 4, Episode 4 : The Sontaran Stratagem

The Doctor reunites with Martha and UNIT as he and Donna face off against the clone hordes of a Sontaran invasion fleet Guest Stars: Freema Agyeman, Christopher Ryan, Ryan Sampson, Christian Cooke, Dan Starkey, Rupert Holliday-Evans, Eleanor Matsuura, Wesley Theobald, Bernard Cribbins, Clive Standen, Radosław Kaim, Elizabeth Ryder, Jacqueline King,