Doctor Who travels back in time to the Roman Empire in the next series of the sci-fi show.

The Time Lord, played by David Tennant, and his companion Donna (Catherine Tate) arrive in Pompeii in AD 79, on the eve of the historic eruption of Mount Vesuvius.

They are faced with either rescuing the residents or leaving them to fend for themselves.

Peter Capaldi, who played spin doctor Malcolm Tucker in The Thick Of It, guest stars as banker Caecilius.

The episode was filmed inside Rome’s legendary Cinecitta studios, which was transformed to look like Pompeii.

Doctor Who executive producer and head writer Russell T Davies said: “Arriving in Pompeii marks the start of another exciting adventure for The Doctor and Donna.

“Donna is stunned to find herself in the midst of history’s most famous volcanic eruption.

“Viewers can expect many more ambitious storylines and a whole host of guest stars in 2008.”

The fourth series of Doctor Who is now in production and will go out on BBC One in spring next year.

The new series will also feature an alien emergency in modern day London and an encounter with murder mystery novelist Agatha Christie.

Other guest stars include Howards’ Way actress Tracey Childs and Rose And Maloney actor Phil Davis.