It’s very interesting what’s happened to Jenna. Everyone knows Capaldi’s going to be great but I think the shocker is just how great he makes Jenna. From a Doctor she could sort of control, because he had a crush on her, she’s landed with a Doctor who barely registers that she’s a girl. They’re great friends and all that but she has to be his human interface with everybody else. She’s much funnier, more exasperated.
Steven Moffat on changes for Clara in the new series (SFX)