Liberta Ellensdottir

 lived in Iceland in 5017. Like many others, she tried to attend a Christmas party given by Nicholas Santana, but since she didn't have an invitation or a donation, she was sent to the lower levels to work, with the promise of being able to attend the party on the twelfth day.

Libby, assigned to wrap presents, included bombs in the presents as a way of disrupting the party. The Sixth Doctor used some of Libby's bombs to stop Santana from flooding the lower levels with magma. (PROSE: Revellers of Doom)