Steven first appears in the serial The Chase, when the Doctor and his companions, Ian, Barbara, and Vicki, find him on the planet Mechanus[1] where he crash-landed two years before.

He joins the Doctor and Vicki as a companion in the following serial, The Time Meddler, when they discover that he stowed-away in the TARDIS after having escaped the burning Mechanoid City.

Steven follows the Doctor through The Daleks' Master Plan, a dark and dangerous adventure that takes the lives of Sara Kingdom and Katarina.

He rejoins the Doctor, however, at the same time that they acquired a new travelling companion, a young woman by the name of Dorothea "Dodo" Chaplet, who is apparently a descendant of Anne's.

An older Steven, still played by Purves, returns in an episode of the 60th anniversary spin-off Tales of the TARDIS, alongside Maureen O'Brien as Vicki.