“We wanted to do a proper, fully-fledged multi-Doctor story for this very special occasion,” says writer, director and executive producer Nicholas Briggs, “and it’s wonderful that all the surviving classic Doctors threw themselves behind the project so enthusiastically. That’s not to say the first three Doctors don’t appear – we wanted to pay homage to the whole history of the classic series.”

The Doctors will also be joined by a number of their regular companions: Louise Jameson reprises the role of the savage Leela, Sarah Sutton plays the scientist Nyssa, Nicola Bryant is American botany student Peri, Sophie Aldred is streetwise kid Ace and India Fisher returns as Edwardian adventurer Charley Pollard.

“And that’s not all,” says producer David Richardson, “because Geoffrey Beevers is back to create mayhem as the Master, and there will be a number of appearances from some much-cherished old friends from the TV series…”

Doctor Who: The Light at the End will be released in two different versions. A five-disc limited special edition comes with two hour-long documentaries, plus The Revenants, a Companion Chronicles tale which began life as a free Doctor Who Magazine download. It’s performed by William Russell, who starred in the very first TV story as Ian Chesterton. The special edition comes in beautiful special packaging, and will include a number of exclusive professionally photographed images of the cast.

The standard edition comprises two discs, featuring the two hour-long episodes of the story.