The Sontaran Stratagem is the fourth episode of the fourth series of
the British science fiction television series Doctor Who, which
depicts the adventures of a time-travelling humanoid alien known as
The Doctor. The episode was broadcast on BBC One on 26 April 2008. The
episode and its sequel, "The Poison Sky", were written by Helen
Raynor, who previously wrote the linked episodes "Daleks in Manhattan"
and "Evolution of the Daleks" in the third series."The Sontaran
Stratagem" features the first appearance of the alien Sontarans to the
series since the 1985 Colin Baker story The Two Doctors, as well as
former companion Martha Jones (Freema Agyeman), last seen in "Last of
the Time Lords." The episode takes place on present-day Earth, where
Martha and UNIT summon the Doctor (David Tennant) for assistance
concerning ATMOS, a revolutionary piece of green technology installed
in 400 million cars worldwide. ATMOS is later revealed to be part of a
Sontaran plot to poison the atmosphere.Show runner Russell T Davies
had considered making the Sontarans return since the revival of the
series and wanted to show changes in Martha's personality after her
departure. The episode was viewed by 7.06 million viewers after its
original broadcast, with an Appreciation Index of 87. Critics gave
generally positive reviews, praising the return of the Sontarans,
Christopher Ryan's portrayal as Staal, and Raynor's writing; some
stated Raynor improved from her previous episodes. The Sontaran Stratagem Biography, NetWorth, Height, Age, Weight, Family, Married, Son, Daughter