Sara Kingdom is an agent in the Space Security Service, with a reputation for being ruthless, hard and efficient. She encounters the Doctor and Steven on Earth, during their flight from the Daleks in the company of her brother, Bret Vyon. Believing Bret to be a traitor, Sara kills him, then pursues the Doctor and Steven - but after being transported to the planet Mira with them, and learning the truth about Bret, Sara allies herself with the Doctor.
Sara has long, straight red hair, green eyes, and high cheekbones. When on duty, she wears her SSS uniform and tall boots, and carries a blaster around with her. Sara is very capable with the blaster, and very confident generally - she carries herself with authority and is not easily intimidated. Sara has a fiery personality to match her hair, and has no trouble stating her opinions or holding her own in an argument. She is also an accomplished fighter, whether she uses her fists or her extensive knowledge of judo.
Sara also has some technical knowledge, and is even capable of repairing machinery that is not completely familiar to her. She is a pragmatist, judging situations in an unbiased manner and arriving at the most logical conclusion or course of action. And, no doubt due to her efficient manner, Sara can then formulate a plan and determinedly carry it out.
Her travels with the Doctor are, sadly, brief; she aids the Doctor in defeating the Daleks' conquest of the universe, but when the Doctor activates their Time Destructor, Sara helps him carry it back to the TARDIS and is ultimately overcome by the effects of being in such close proximity to it. Before the eyes of the Doctor and Steven, Sara ages into an old woman and then dies, even her skeleton rapidly disappearing.
