Carfrae Morgan

 was a student who was part of a ghost-hunting group. The Second Doctor, Ben and Polly met the group at the Grange, a haunted house they were investigating. Later, when the group was trapped in the house and it was going to be destroyed, they were rescued when Dent and Wilding sent the TARDIS back from the future to just before the explosion. (PROSE: Invasion of the Cat-People)