Season 1

Series 1 introduced the Ninth Doctor, along with new companion Rose Tyler. It dealt with the words “Bad Wolf” being spread across time and space, which was the main arc of the series. This meme was seen in the majority of the episodes.
Series 1 also provided the first major information about the Last Great Time War. The Parting of the Ways featured the revived series’ first regeneration. The season also introduced Jack Harkness and planted the seed for the spin-off Torchwood.

1 Rose Russell T Davies Keith Boak First appearances of the Ninth Doctor, Rose Tyler, Jackie Tyler and Mickey Smith. Reintroduction of the Autons and the Nestene Consciousness.
2 The End of the World Russell T Davies Euros Lyn First appearance of the Face of Boe and Cassandra.
3 The Unquiet Dead Mark Gatiss Euros Lyn Introduction of the Cardiff Rift. Eve Myles guest stars in a role other than Gwen Cooper.
4 & 5 Pt. 1: Aliens of London
Pt. 2: World War Three
Russell T Davies Keith Boak First appearance of Toshiko Sato, Harriet Jones and the Slitheen (Raxacoricofallapatorians).
6 Dalek Robert Shearman Joe Ahearne Reintroduction of the Daleks and first appearance of Adam Mitchell.
7 The Long Game Russell T Davies Brian Grant Final appearance of Adam Mitchell.
8 Father’s Day Paul Cornell Joe Ahearne Introduction of Pete Tyler (Rose’s father).
9 & 10 Pt. 1: The Empty Child
Pt. 2: The Doctor Dances
Steven Moffat James Hawes First appearance of Jack Harkness.
11 Boom Town Russell T Davies Joe Ahearne Reappearance of the Slitheen.
12 & 13 Pt. 1: Bad Wolf
Pt. 2: The Parting of the Ways
Russell T Davies Joe Ahearne Final appearance of the Ninth Doctor portrayed by Christopher Eccleston and introduction of the Tenth Doctor portrayed by David Tennant; last regular appearance of Jack Harkness until Utopia. Reappearance of the Daleks.