The TARDIS materializes in France in 1572. Tensions between Catholics and Protestants are becoming violent. The Doctor visits the apothecary, and Steven—the only remaining companion—goes to a tavern and strikes up a friendship with a Huguenot named Nicolas Muss (David Weston). When The Doctor does not return, Steven goes to his new friend’s home, where a frightened serving girl named Anne Chaplet (Annette Robertson) tells them she overheard Catholic guards discussing a possible massacre of Huguenots. Nicholas sends her to his master, Admiral de Coligny, for safety.
The Doctor turns up and when Anne tells him the date, he realizes the St. Bartholomew’s Eve Massacre is about to take place. He sends Anne to stay with her aunt and he and Steven leave in the TARDIS just as the massacre is beginning.
Steven is distraught that the Doctor abandoned Anne, even though the Doctor insists he cannot change history. When the TARDIS lands in London in 1966, he decides to leave. The Doctor is alone for the first time. A young girl comes in to use the police box to report an accident. Steven returns to warn the doctor that the police are on the way and he takes off in the TARDIS, not noticing that the girl is still aboard. She is Dodo Chaplet, the descendant of Anne Chaplet, who obviously survived the massacre.
The first ten Doctor Who stories featured the same three companions, and two of them remained for another six. In this stretch of five lost stories, however, we begin with Vicki and Steven, Vicki leaves and Katarina joins, then Sara joins and both she and Katarina die. Then Dodo joins. Throughout, Steven is nearly killed several times and even walks out on The Doctor at one point. All in stories we cannot see.