Doctor Who is a popular science fiction program that features an alien Time Lord who travels through time in a blue police call-box called the TARDIS. He travels with human companions through time trying to solve problems, avoid major catastrophes and maintain a balance in the universe.

The most recent series of Doctor Who, which kicked off in 2005 and starred Christopher Eccleston as the Doctor, has spun-off two different series: Torchwood and The Sarah Jane Adventures. Both shows exist in the same universe and the main characters at one time or another had contact with the Doctor.

Doctor Who Season Four begins with bridge episode Voyage of the Damned, which originally aired in England on December 25, 2007. The first episode of the season premiers on April 5th, 2008, when Donna Noble calls upon her old friend, the Doctor, to help foil the dark plans of over-the-top entrepreneur Miss Foster.

Throughout the season, the Doctor will have two other companions as well. Many fans will rejoice as Billie Piper returns for three episodes to play Rose Tyler. Freema Agyeman will also return to play Martha Jones for five episodes.