Bianca (Interlude)
From Tardis Wiki, the free Doctor Who reference
Bianca was an assistant stage manager on a theatre set. She encountered the Fifth Doctor when he landed on her set. (AUDIO: Interlude)
The Doctor would eventually discover that Bianca, along with many other people throughout history who looked like her, were caused by a group of Time War Daleks who — while on a mission to prevent the rise of Time Lord society on Gallifrey — created a time distortion which created alternate versions of themselves as four un-mutated Kaled people. This time distortion also caused there to be multiple copies of these four Kaleds to appear at various points throughout time and space. (AUDIO: Effect and Cause’')
