With John Simm returning as The Master in this Saturday's Doctor Who, we reveal more about his return and provide a brief rundown on the history of the evil Time Lord...

There’s a welcome return for two classic foes of The Doctor when the two-part series finale kicks off . It will see the Doctor and Bill facing Mondasian Cyberman, while Missy meets The Master, played again by John Simm for the first time since 2010.

The Doctor and co arrive on a huge spaceship that’s 400 miles long and 100 miles wide and about to be sucked into a massive black hole. Viewers will find out far more about The Master’s earlier history with The Doctor over the two epsiodes, and The Master is in particularly menacing form.

“Thanks to the power of time travel I’m back as The Master,” said John Simm. “It’s always a pleasure to work with this great team of people and I can’t wait for fans to see what The Master gets up to.”

The shock return inevitably means the Master comes face to face with Missy (Michelle Gomez), even though they’re the same person. As fans will know, Missy is a later incarnation of the Time Lord after he regenerated into her. As both are time travellers, it’s led to the two incarnations finally meeting up, something which executive producer Steven Moffat, who’s written this adventure, had been keen to make happen for a long time

“I’d always thought it would be fun to have a story where two versions of the Master meet,” he said. “It’s not often you get to see a solo personality clash between characters, and it’s been a huge pleasure to have fan favourites John Simm and Michelle Gomez face to face in the same role.”

Here’s our complete guide to everything you might want to know about The Master in Doctor Who…

* The Master is a renegade Time Lord who grew up with the Doctor on their home planet Gallifrey. The pair had been childhood friends, but The Master turned evil. He first appeared in Jon Pertwee’s 1971 adventure Terror of the Autons played by the late Roger Delgardo. He was subsequently played by a succession of different actors including Anthony Ainley, Peter Pratt, Geoffrey Beevers and Derek Jacobi.

* John Simm first appeared as The Master in the 2007 episode Utopia when he took over from Derek Jacobi, whose Master was a kindly biologically human scientist known as Professor Yana. It was the very first time The Master was shown regenerating on screen.

John Simm’s meglomaniac Master as he took on David Tennant’s Doctor

* Throughout his time as The Master, John was the nemesis of David Tennant’s 10th Doctor and companions Martha Jones (Freema Agyeman), Jack Harkness (John Barrowman) and Donna Noble’s grandfather Wilfred Mott (Bernard Cribbins).

* John also appeared in four further Doctor Who episodes, The Sound of Drums, Last of the Time Lords and the 2009/2010 two-part Christmas special The End of Time. In each one The Master was haunted by a constant drum beat in his head.

A sinister Christmas with David Tennant’s Doctor and Bernard Cribbins as Wilfred

* Last of The Time Lords saw the apparent death of The Master. But John Simm made a comeback as a manic blond-haired version of the villainous Time Lord in The End of Time when he was resurrected using a piece of his body. He went on to control the Earth by turning every human into an exact copy of himself, including the then US President Barack Obama!

* John was last seen as The Master on New Year’s Day 2010 when the Master sacrificed himself while Time Lord President Rassilon (Timothy Dalton) tried to kill the Doctor.

* Missy is the latest incarnation of The Master, who regenerated into a female. Missy is a shortened name for ‘Mistress’.

John Simm can be seen back in Doctor Who on BBC1 this Saturday at 6.45pm