The first series features Christopher Eccleston as the ninth incarnation of the Doctor, his only series in the role, accompanied by Billie Piper, as his first and main companion Rose Tyler, whom he plucks from obscurity on planet Earth, and to whom he grows increasingly attached. He also travels briefly with unruly boy-genius Adam Mitchell, played by Bruno Langley, and with 51st-century con man and former "Time Agent" Captain Jack Harkness, portrayed by John Barrowman. Episodes in the series form a loose story arc, based upon the recurring phrase "Bad Wolf".

One gunshot, one death, one moment out of time that irrevocably links eight minds in disparate parts of the world, putting them in each other's lives, each other's secrets, and in terrible danger. Ordinary people suddenly reborn as "Sensates."

Plagued by strange memories, Neo's life takes an unexpected turn when he finds himself back inside the Matrix.

Before she was a fashion icon, before her column in the New York Star, before Mr. Big, Carrie Bradshaw was an innocent 16-year-old girl living in suburban Connecticut.

The series stars David Tennant as the Doctor. In the Christmas special he is joined by Catherine Tate as Donna Noble. The series also introduces Freema Agyeman as the Doctor's new companion Martha Jones. John Barrowman also reprises his role as Captain Jack Harkness in the final three episodes which serve as the finale. The series is connected by a loose story arc consisting of the recurring phrase "Vote Saxon".