The Three Doctors (Doctor Who) the Third Doctor (Jon Pertwee) for help when Omega drains their civilisation's power. The serial opened the tenth anniversary year of the series, and features the first three Doctors all appearing in the same serial. This makes it the first "Doctor Who" story in which an earlier incarnation of the Doctor returns to the show. A superluminal signal is sent to Earth, carrying with it an energy blob that seems intent on capturing the Doctor. The homeworld of the Time Lords is also under siege, their power being drained through a black hole. Trapped themselves, and desperate to send help,
The Doctor (Doctor Who) it is revealed that he also left to investigate the mystery of why good prevails in a universe where evil would seem to have so many advantages. It would be during his twelfth incarnation that the Doctor realizes his actions made the difference in the balance between good and evil in the universe. In other media, more has been revealed of the Doctor's early life. In the Past Doctor Adventures novel "Divided Loyalties", the Doctor recalls his Academy years in a dream induced by the Celestial Toymaker. According to this, he was a member of an organisation called the Deca,