4-th episode of 4-th season "Doctor Who"

What "Doctor Who" 4-th episode about

Location: Modern-day Earth Date: 2009Enemies: Sontarans The Doctor 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?

Episode number: 4

Episode name: "The Sontaran Stratagem (1)"

Episode release date: 26 april 2008 at 18:00

Status: aired