The showrunner told Doctor Who Magazine that the character of Sky Silvestry was created especially for the acclaimed actress, saying: "We needed the absolute best for this episode, and we got them. I suggested Lesley - I actually wrote it thinking of her - because I'd been dying to work with her again and she'd keep asking to be in Doctor Who."
He continued: "She'd send me emails asking to be the Queen of Outer Space, which isn't exactly what she got, but this is better, probably. Technically, the part of Sky is the hardest thing I've ever asked an actor to do, and Lesley's simply astonishing."
Sharp previously starred in both Bob and Rose and The Second Coming by Davies.
> Click here for our review of the Doctor Who episode 'Midnight'