BBC News said:
Filming is underway for Series Four of Doctor Who, with Catherine Tate reprising her role as Donna, the runaway bride featured in last year's Christmas Special.
The start of the new series will see Donna tracking down the Time Lord during an alien emergency in modern-day London. The couple are destined to experience a series of wonderful adventures throughout the new series including meeting one of Doctor Who's most popular aliens, The Ood in a brand new episode, Planet of The Ood.
Catherine Tate said: "I am delighted to be returning to Doctor Who. I had a blast last Christmas and look forward to travelling again through time and space with that nice man from Gallifrey."
Donna and The Doctor will also be travelling through time for an encounter with the legendary murder mystery novelist, Agatha Christie, played by Jekyll star Fenella Woolgar. Fenella will be joined by The Good Life actress Felicity Kendal, who will star as Lady Clemency Eddison.
"What a brilliant idea that Agatha Christie and Doctor Who should meet!," noted Matthew Prichard, Agatha Christie's grandson. "Two characters whose contribution to British entertainment is absolutely unrivalled. As far as I know my grandmother, Agatha Christie, never saw Doctor Who, but I am sure she would have been intrigued, excited and above all flattered by all this attention in 2007."
Doctor Who's executive producer and head writer, Russell T Davies comments: "Visiting Agatha Christie has been on my wish-list for ages now, and for the Doctor, it's a real meeting of minds! Viewers can expect many more ambitious storylines and a whole host of guest stars in 2008."
Blackadder and Notting Hill Actor Tim McInnerny will also guest star later in the series.
Freema Agyeman who has played Martha Jones, The Doctor's companion throughout the critically acclaimed third series will return to the show to join The Doctor and Donna mid series.
First Official News from next year!!!
Edited by Rappy, 10 October 2011 - 16:21.