Let's Kill Hitler

"Let's Kill Hitler" is the eighth episode of the sixth series of the British science fiction television series "Doctor Who". The episode was broadcast on BBC One, Space and BBC America on 27 August 2011. It is the second episode of a two-part story. The story began with "A Good Man Goes To War" (episode seven). It is the 778th episode. 
The episode centers around River Song and the history of Amy Pond.