Amy, Rory and River mourn the Doctor, but are soon plunged into an adventure with President Nixon and the Silence!
Amy Pond, Rory and River Song are summoned to Utah, USA, by the Eleventh Doctor, who is killed by a mysterious figure in a space suit. The dead Doctor is revealed to be an older self, after his younger version returns. They try to understand what the future Doctor said and are sent to Washington D.C. The team deals with the Silence, a race of aliens with the ability to make people forget their encounter with them when they look away.
The Silence was created to compete with other past aliens in terms of “scariness,” including the Weeping Angels. The episode was partially filmed on location in Utah; the first time in Doctor Who that principal photography took place in the United States. The episode was dedicated to Elisabeth Sladen, known for playing former companion Sarah Jane Smith, who died from cancer on 19 April 2011.