Steven Moffat has teased big changes in Doctor Who's eighth season ahead of the show's return to BBC One in August.
The show's head writer spoke about Peter Capaldi's casting at Hay Festival, saying that the new Doctor will bring about the show's biggest changes since 2005.
"We haven't made much of change to Doctor Who since it came back in 2005," he said.
"It's been the same show. It's maybe amped some things up and lowered some other things, but it's basically the same.
"I just felt it needs to be a bit more different now. It's needs to be surprising again!"
Moffat added that casting a "handsome, yet quirky, young man with entertaining hair" would have resulted in the long-running show becoming too predictable.
"It would have just exposed the formula," he claimed. "We'd have found somebody great and people would have liked him, but the show would have just become that little bit more ordinary."