Told that Vyon is a traitor by Mavic Chen, the Guardian of the Solar System (who was in league with the Daleks) and ordered to kill whoever is working with him, she shoots her brother and is about to do the same to the Doctor and Steven when they are transported across space to the planet Mira.

There she learns, to her horror and grief, that her unquestioning obedience has not only led her to unjustly kill her brother, but also that by doing so she has prevented Vyon from warning Earth of the Dalek plot.

When the Doctor activates the Time Destructor—a device that accelerates time—as part of his plan to stop the Daleks, he orders his companions back to the TARDIS for their protection.

Jean Marsh reprised the role for the Companion Chronicles range of Big Finish Productions audio dramas, set just after the Christmas episode.

In The Guardian of the Solar System, it is revealed that the TARDIS traveled back in time and Sara unintentionally met Mavic Chen over a year before the events of The Daleks' Master Plan.

In the first drama produced, Home Truths, The Doctor, Steven and Sara found a house in Ely in the far future that was so advanced, its abilities seemed like magic.

Sara implanted a copy of her consciousness into the house to give it a human perspective to make decisions in the future, and it lived with her voice and mind and memories for over a century.

Sara is suddenly reborn in a new version of her original body, albeit slightly older and with a thousand years of memories.

A ghost-like illusion of Kingdom, alongside Katarina and another deceased companion, Adric, appears in the Virgin New Adventures novel Timewyrm: Revelation by Paul Cornell.

[11] Marsh herself said in a 2003 interview for the Loose Cannon telesnap reconstruction that she would "definitely not" have continued in the role past Master Plan, even had it been offered to her.

A Production Diary compiled by David J. Howe, Mark Stammers and Stephen James Walker from contemporary memos and correspondence notes that producer John Wiles and story editor Donald Tosh employed Sara Kingdom as a "short-term companion...[to] be killed off at the end of [The Daleks' Master Plan]".

Marsh would return to the programme in the 1989 serial Battlefield, playing Morgaine, coincidentally with Nicholas Courtney as Brigadier Lethbridge-Stewart, thus appearing in both his first and last regular Doctor Who episodes.