Jane was the Doctor's best friend in Gallifrey (she is a time lord) when they were children. But when she was young, she was kidnapped to work at the Library, a library for all creatures of the universe. She has been watching the Doctor throughout all his life, through a special telescope she devised to see anywhere and anytime in the universe. She escaped when the Doctor visited the Library and exposed it's secret: all of the books had subliminal messages to always obey the dales. She soon became the Doctor's companion, and ended up marrying him in the TARDIS.