The fourth season of the new Doctor Who is set to blast back to our screens from April 5th as David Tennant and new assistant Catherine Tate embark on a fresh batch of inter-galactic, time-travelling adventures.

Fans of the rejuvenated sci-fi show have been left licking their lips following a BBC teaser trailer showing the Doctor along with previous assistants Martha Jones (Freema Agyeman) and Rose Tyler (Billie Piper) along with new assistant Donna Noble (Tate). There are also rumours of a return to the screen for Davros, the notorious creator of the Daleks, along with many other fearsome enemies which will have the audience cowering behind their sofas.

Russell T Davies, writer of the new Doctor Who series, was thrilled that Tate decided to become the new assistant full-time describing her as an 'absolute star' during the Christmas special two years ago. Following confirmation of her return to the show 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."

The first episode of the new series - Partners in Crime - will see Donna re-united with the Doctor for the first time since the 2006 Christmas special. Sarah Lancashire, whose stock continues to rise following a glorious performance as Mrs Corney in the BBC's latest adaptation of Oliver Twist, plays the villainous Miss Foster in the first episode, and is just one of a host of stars, including Felicity Kendall and Peter Capaldi, set to appear in the fourth series.

The BBC have been tight-lipped on the storylines for the new series but they have let slip some intriguing details, such as the inclusion of Agatha Christie as a character. Inevitably the show will dominate the TV listings for Saturday nights, and joins popular spin-offs Torchwood and the Sarah Jane mysteries back on the BBC's timetable.

David Tennant has been one of the key aspects to the success of the show. The Scottish actor has combined quick-witted humour with dashing good looks to win over many viewers who would not usually go near a science-fiction programme. The latest season could prove to be Tennant's last as the Doctor, as he will soon be joining up with the Royal Shakespeare Company to take the part of Hamlet. Rumours are already rife with possible replacements, ranging from Rhys Ifans to Jennifer Saunders.

It has been a good 2008 for Doctor Who so far following huge viewing figures for the Christmas special, Voyage of the Damned (12.2 million) and a Bafta Craft nomination for writer Steven Moffat. The BBC will be hoping that the Doctor can continue their recent viewing figure successes over rivals ITV, Channel 4 and Sky as the year goes on.

To check the times for the new series of Doctor Who, go to www.uknetguide.co.uk/TV/.