Doctor Who: -  The Sontaran Stratagem

This week on Doctor Who: The Sontaran Stratagem, the Doctor (David Tennant) is called back to modern-day Earth by an old friend as an old enemy starts some new troubles.

Aided by the Rattigan Academy, the Sontarans establish a covert base at the mysterious ATMOS Factory. Can the Doctor stop the Sontarans from unleashing a potent terror that will bring the world to its knees?

The Sontarans were first seen in The Time Warrior, an episode of the show in 1973, when Jon Pertwee played the Doctor.

This episode also stars Freema Agyeman as Martha Jones (Doctor Who Series 3, Torchwood), Christopher Ryan as General Staal (The Young Ones, Absolutely Fabulous), and Jacqueline King as Sylvia Noble (55 Degrees North).