Just realized that DW/LJ are the only places I can post with spoiler stuff behind a cut!

So here it goes.

John Simm will return as the Master to battle the Doctor (Peter Capaldi), new companion Bill Potts (Pearl Mackie) and Nardole (Matt Lucas) in the forthcoming series of Doctor Who.

John Simm says: “I can confirm that it’s true, thanks to the power of time travel I’m back. It’s always a pleasure to work with this great team of people and I can’t wait for you all to see what the Master gets up to in the next series. “

Steven Moffat, writer and executive producer, says: "Nothing stays secret for long on Doctor Who but you'll have to wait a little bit longer to see exactly what the Master is up to and how he makes his return to face the Doctor. It’s been a huge pleasure to have fan favourites John Simm and Michelle Gomez face to face in the same role! It’s not often you get to see a solo personality clash."

John Simm was last seen as the Master on New Year’s Day 2010. Viewers will have to wait to see exactly when and how the Master will return to the new series, which starts on Saturday 15 April at 7:20pm on BBC One.

As previously announced, Doctor Who series 10 will also star Michelle Gomez as Missy – a later regeneration of the Master. Other returning foes include the Daleks, the Ice Warriors and – returning for the first time in over 50 years – the Mondasian Cybermen. An exciting line up of new faces and adversaries will debut across the series, including adorable-but-deadly Emojibots and David Suchet as the Landlord.

Doctor Who returns to BBC One with episode one The Pilot at 7:20pm on Saturday 15 April.