Elizabeth Marchwood was the daughter of Lord Marchwood. Her brother, Joseph Marchwood, and she went looking for Erasmus Darkening. He banished them for eternity.
In the early 21st century her "ghost" and her brother's "ghost" tried to warn Sarah Jane Smith about Erasmus. After Sarah Jane and their father defeated Darkening, Elizabeth and her brother were reunited with their father as "ghosts". (TV: The Eternity Trap)
