Petra tried to remain strong when her parents died. This made her emotionless and rather sarcastic. She bought the ship SS Humphrey Bogart and had a cheap crew on it. The only person whom she knew very well was her Uncle Kendle. She met the Tenth Doctor and Rose Tyler on the planet Laylora when her ship landed there. She lost two of her crew members on the planet, including her uncle, and took a boy who had crashed on Laylora when he was a baby in an escape pod. She became his mentor. (PROSE: The Price of Paradise)