“Peter responded incredibly well to Pearl in her audition,” reveals casting director Andy Pryor. “It was like they were feeding off each other, swapping ideas of how they might play the scene. That’s always exciting; it’s full of possibility.”
Out of the final five, it was how Mackie responded to Capaldi that eventually won the day.
“It’s that thing that’s always impossible to put your finger on: chemistry,” says Pryor, who has worked on Doctor Who since it was revived in 2005. “You can’t predict that until you get them in the room together. When we did it became evident very quickly that they had a spark that was new and exciting and fresh.”
When Capaldi and Pryor, along with showrunner Steven Moffat and exec producer Brian Minchin, met up to decide once and for all who would play Bill, Mackie was top of everyone’s list.
“We talked it all through,” says Pryor. “Everybody looked back through the auditions. We shared our views – and it was unanimous.”
The clip announcing Pearl Mackie as Bill is a version of one of those original audition scenes – do you see the “chemistry” Pryor’s talking about?
“I would find it hard to cast a companion without having them in to read with the incumbent Doctor,” says Pryor. “It’s all about that relationship. They are going to spend months together on and off screen.”
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