Posted By John Bowman
With filming having begun on Series Three of Torchwood, the BBC Press Office today said the team would be engaged in a "battle for the future of the human race against the fiercest force they have encountered".
Co-executive producer Russell T Davies said: "The new series of Torchwood is hugely bold and promises to be bigger and better than ever - the audience is in for an amazing ride.
"This series is one big serial and the most ambitious story we've ever made, and we've got plenty of surprises in store."
Fellow co-executive producer Julie Gardner said: "We hope to make Torchwood a gripping and surprising TV event with storylines that push our team into greater danger and sacrifice.
"Joining our main cast are some fantastic guest artists who will only add to making this unmissable TV."
The guest stars are Peter Capaldi - Caecilius in the Doctor Who story The Fires of Pompeii - playing a civil servant called Mr Frobisher "who is hiding a terrible secret", Paul Copely and Liz May Brice.
The five-part series - called Torchwood: Children Of Earth - is being written by Davies, John Fay and James Moran, and directed by Euros Lyn. Produced by Peter Bennett, it will air over one week next year.