P.S. (webcast)

P.S. was a short Doctor Who webisode following The Angels Take Manhattan. It is in the form of an animated storyboard for a scene that was written by Chris Chibnall but not shot, featuring narration by Arthur Darvill as Rory Williams.

Synopsis
Brian Williams receives an emotional letter from his son.

Plot
The Doctor leaves with Amy and Rory after having dinner with them and Brian. A week later there is a knock at the door and Brian answers it. An American man stands there; he passes Brian a letter and walks in. Brian sits in the lounge and reads the letter revealing it is from his son Rory and that he and Amy had a wonderful life in New York, "fifty years before [Rory] was born," and adopted a son who turns out to be Anthony.

Cast

 * Rory Williams (voice) – Arthur Darvill
 * Also incorporates footage from TV: The Power of Three with Matt Smith, Karen Gillan, Darvill and Mark Williams

Story notes

 * This scene was originally meant to be a DVD extra, but was not filmed due to actor availability issues.

Continuity

 * The Angels Take Manhattan vaguely implied that Amy and Rory had been sent back from the cemetery to circa 1938, the past era to which Rory was first sent. This is confirmed. Rory is shown in Let's Kill Hitler to have been Amy's schoolmate, roughly the same age, and Amy was 7 years old in 1996 (TV: The Eleventh Hour). 50 years, whether literal or rounded off from 51 years, places the start of their new life c. 1938.
 * The Angels Take Manhattan implied that Amy and Rory remained in or about New York City. P.S. confirms this. Anthony's sister was in New York during their parents' lifetimes, both as adult River Song in the summer of 1969, and as young Melody and infant Mels in January 1970. (TV: Day of the Moon)
 * Anthony is stated to be in his mid-sixties, and to have adopted as an infant in 1946. The epilogue of The Doctor, the Widow and the Wardrobe was set at Christmas 2013, more than two years after Amy and Rory last saw the Doctor. Pond Life followed during the spring and summer of no earlier than 2014, Some months or more had passed before Asylum of the Daleks in which Amy and Rory are signing their marital separation agreement. The Power of Three begins in an July of a year no earlier than 2015 and ends in July of the following year, no earlier than 2016. Brian's lack of reaction to Rory's assertion of being thirty years old at the time of Dinosaurs on a Spaceship implied that their "present" was in 2018 or 2019. Amy and Rory were still in the present in The Hungry Earth, set in 2020. All of this places the end of The Power of Three and P.S. in or after 2020, by which time, Anthony would be in his mid-seventies, barring time-travel.
 * Rory says that he "realize[s] having a grandson who's older than you is so far beyond weird". Rory grew up with his own daughter and also knew her as a woman considerably older than himself. Even in their youths, Mels was already several years older than Rory and Amy, despite appearing to be their age.
 * Asylum of the Daleks established Amy's inability to bear additional children after Melody, resulting from the events at Demon's Run. (TV: A Good Man Goes to War)
 * Amy and Rory are the second and third former companions shown to have adopted children, after Sarah Jane Smith (TV: Invasion of the Bane, Sky) Ben Jackson and Polly Wright were said to have operated an orphanage in India. (TV: Death of the Doctor)
 * Brian waited a week for his letter, whereas Sally Sparrow and the Doctor received theirs within minutes of their respective friend's disappearance. (TV: Blink, The Angels Take Manhattan)
 * Rory mentions that he bought a trowel, in response to Brian's suggestion. (Dinosaurs on a Spaceship)
 * Brian is watering the plants when Anthony arrives, as he told the Doctor he needed to do. (The Power of Three)