Katarina is introduced in the serial "The Myth Makers", which takes place during the siege of Troy around 1200 BC. She is a handmaiden of the prophetess Cassandra, who was also the princess of Troy. Before meeting the Doctor she was little more than a slave. During the Myth Makers, she was sent by Cassandra to spy on the First Doctor and his friends, particularly Vicki, known to her as Cressida. Katarina befriends Vicki, who sent her to help the Doctor get Steven back into the TARDIS after a spear thrust had badly injured him. Katarina tended to his wounds and helps the TARDIS crew survive the events of the Troy siege. She joins Steven and the Doctor on their travels while Vicki decides to stay behind in Troy with the warrior Troilus.