Derek Jacobi said: "The Master’s a great part to play – he's very dramatic, but he's also very funny. Occasionally he gets a bit big-headed, but he has many layers to him. And he's a wicked old fart, isn't he? The hero who’s a knight in shining armour is really a boring old sod. He’s got to have faults, and the Master's full of faults."

Producer Robert Valentine added: "When the Master returns, we’re going to see him facing an existential crisis. The Daleks and the Time Lords both want him dead, and he wants out of the Time War. However, he knows in his hearts of hearts that there is no way out, and a desperate, despairing Master is a very deadly Master indeed.

"There are some deliciously dark and wickedly funny adventures in store, and at the centre of it all is Derek Jacobi’s towering performance. It’s been an absolute dream working with Derek, and through these stories we’re getting to see many different sides of his Master’s character.

"Watching him transform from a charming lady-killer one minute to a rat in a trap the next, or from a kindly grandfather into the very devil has been a thrill. This is very much a Master who sees no hope for the universe or for himself, and is trying to console himself by helping it burn. And he'd very much like you to join him."

Sir Derek Jacobi © Tony Whitmore