Sir Derek Jacobi said: "The good thing about the Master is that he can be anybody. He morphs all the time. With this script, I liked both the comedy and the nastiness. Villains and nasty people are often the best parts – the goodies go unremarked!"

James Marsters said: "I was shaking in my boots to perform alongside Derek Jacobi. He’s one of the best of the best. I’ve been watching him since I was very young. He’s got a combination of playfulness and anger and love and hate, all boiling around inside him, along with an incredible technical facility, all together in one making it look effortless!

"Captain John’s still very much himself. He’s just as fun to play, he’s just as morally ambiguous – that’s probably the most generous term you could use for him! He’s always had a latent hero inside, almost never realised; he does the right thing every so often so that you can just feel it’s there in him."

Lisa Bowerman