Peter Capaldi has strongly hinted that we will see a different regeneration for the 12th Doctor.

Speaking to the NYTimes, Capaldi revealed: “There’s this notion now that it’s the same process he’s gone through every time, and that’s not true. It’s only the last couple of regenerations that have been, as it were, fairly straightforward ones. I can’t go into the details of a lot of it, because I know what happens, but I don’t know how it happens.”

Capaldi also elaborated on why it was time to move on: “They asked me to stay on. And I love this show. But I began to get worried about my capacity to deliver my best work. The schedule is very intense, and I began to wonder, how many different ways can I find to say, “The time vortex is going to open up and destroy the entire universe as we know it, unless we blow up that model spaceship over there”? It concerned me that if I did more, yes, I’d be able to do it, but I’d just be phoning it in. And I didn’t ever want to be in that situation.”