Dr. Who opened its new season with a bang, literally, and in America, complete with the Doctor (Matt Smith) wearing, albeit briefly, a Stetson. In part one of a two-parter the Doctor, in the first few moments of the episode, was shot and killed by a mysterious figure in a 1960s-era American space suit. Will Amy (Karen Gillan), Rory (Arthur Darvill) and River Song (Alex Kingston) be able to prevent this from happening by doing some creative time-traveling? And who is this old man who calls himself Dr. Canton Everett Delaware 3rd who shows up just in time wth some gasoline in a can to help give the Doctor a Viking funeral?
Before the disaster of the Doctor being shot, the time travelers all received mysterious numbered “TARDIS blue” envelopes — presumably invitations from the Doctor. As they sit down to a picnic in the American West, the Doctor is, per usual, talking a mile-a-minute about his age, 1103 (older than Amy remembers) and 1969, "Human beings — I thought I'd never get done saving you." They look over towards a nearby lake and see an astronaut in the water. The Doctor approaches the lone figure, "It's OK, I know it's you." Bang, bang, bang.
After the shooting and subsequent disappearance into the lake of the astronaut, the three try to regroup, when in bounds the Doctor, apparently an early version of himself. Now Amy is determined to not let what they just experienced happen again. River tells her that she was thinking along the same lines.
The Doctor greets River with, "Dr. Song who are you? You're someone from my future, but who?" River Song is a time-traveling future companion of the Doctor, and as she tells Rory, they are going in opposite directions in time. Each time she sees him, he remembers her less, until eventually he won't know who she is at all. It's tragic, really, as it is clear, like Amy, that she cares deeply for him. She has been in prison, "for killing the best man she had ever known." Considering the first scene, that sounds especially ominous.