Charles, Prince of Wales, meets a young Diana Spencer at her family home in Sandringham whilst picking up her elder sister Sarah, to go on a date.
Margaret Thatcher's Conservative Party win the 1979 election, and she becomes the first female Prime Minister of the United Kingdom.
Charles reads the contents of Mountbatten's letter, writing critically of his affair with the married Camilla and instructing him to find a suitable wife, whom the public will love as a princess and, in due course, as queen consort.
Charles meets Diana again at Badminton, who passes on her condolences about Mountbatten and praises him for eulogising his funeral.
Diana, now living in a flat in Earls Court with her friends, travels back to Sandringham to meet Charles.
"Gold Stick" was written by the series creator and executive producer, Peter Morgan, and directed by Benjamin Caron.
[1] In September 2019, Gillian Anderson, who had been rumoured since that January to be in talks to portray Margaret Thatcher in the fourth season, was officially confirmed for the role.