Major Twists & Season Turns:
- Season 1: Rose Tyler absorbs the Time Vortex, becoming the omnipotent "Bad Wolf," disintegrating the Dalek fleet and resurrecting Jack Harkness; Nine absorbs the energy to save her and regenerates into Ten.
- Season 2: Cybermen and Daleks clash; Rose is trapped forever in a parallel universe, separating her from Ten.
- Season 3: Yana reveals himself as The Master using a fob watch; he takes over Earth as Harold Saxon.
- Season 4: Davros constructs a Reality Bomb to erase all matter; Donna absorbs Time Lord intellect ("Doctor-Donna"), but to save her burning brain, Ten erases all her memories of him.
- Specials (2009–2010): Ten saves Wilf from lethal radiation, accepting his demise before regenerating into Eleven.
- Season 5–6: The cracks in time stem from the TARDIS exploding; River Song is revealed to be Amy and Rory's daughter, raised to assassinate the Doctor.
- Season 7 / 50th: Clara Oswald splits into infinite versions of herself across time to save every Doctor incarnation. Ten, Eleven, and War Doctor retroactively freeze Gallifrey in a pocket universe.
- Season 8–10: Missy is revealed to be a female Master who creates Cybermen from human corpses. Twelve spends 4.5 billion years in a confessional dial to save Clara, but they erase Twelve's memories of her to save the universe.
- Season 11–13: The Master destroys Gallifrey after discovering "The Timeless Child": the Doctor is not a native Time Lord, but an immortal species from another universe whose genetic code was harvested by Gallifreyans to create regeneration.