The final scene from "The Power of Three" is shown, before the titles.
Afterwards, in complete drawing format, Brian is shown watering the plants, when there is a knock at the door. A man, Anthony, from New York, hands Brian a letter. Anthony tells Brian that he'll wait indoors until he has read it.
Brian sits down and reads the letter, which is from his son Rory. It explains that Brian will never be able to see him or Amy again, and he apologises. Rory also explains that the person who delivered the letter is Brian's grandson, Anthony Brian Williams, whom Amy and Rory adopted in 1946.
After Brian reads the letter, he walks out to Anthony, who offers a handshake. The two then embrace in a hug as the episode closes.
"P.S." is a mini episode of the seventh series of Doctor Who, written by Chris Chibnall. Set after the departure of Amy Pond and Rory Williams in "The Angels Take Manhattan", it depicts a letter that Rory sent to his father Brian explaining why he and Amy are not returning. This episode was dubbed "the scene that was never shot", as it was released in complete storyboard drawings.