The Watcher (Logopolis)


 * See The Watcher for the episode.

The Watcher was a manifestation of the Doctor that appeared a few hours before the regeneration of his fourth incarnation into his fifth. He appeared to the Doctor himself and his companions and brought Nyssa to the planet Logopolis.

Biography
The ghostly figure of the Watcher had a white, featureless, unformed face and body and white clothes. Though he would use The Doctor's TARDIS later, he apparently had the power to traverse time and space without external aid.

He was first seen silently observing events on Earth, particularly the events leading to Tegan Jovanka entering the Doctor's TARDIS. It was around this time that the Doctor first noticed the Watcher.


 * It is not known for how long the Watcher had been observing the Doctor.

Although silent, the Watcher was capable of communication, and communicated with the Fourth Doctor and, later, his companion, Adric. The Watcher apparently on his own accord transported Nyssa from Traken, a planet which would soon die due to the entropy wave, to Logopolis and safety. Later, apparently working on the Doctor's instructions, he piloted the TARDIS from Logopolis to keep Adric, Nyssa and Tegan safe. It was during this voyage that the Watcher engaged Adric in a private conversation.

At the moment of the Fourth Doctor's death, the Watcher appeared and merged with the Doctor to create the Doctor's next incarnation. (DW: Logopolis)

Categories

 * Exactly how and why the Watcher was created remains a mystery; to date no similar creature is known to have manifested in connection with any other of the Doctor's regenerations. However, a highly advanced Time Lord, K'anpo Rimpoche, had apparently manifested his future regeneration as his assistant, Cho Je, before regenerating into Cho Je's form. It was in this form that he then manifested a short time later during the Doctor's third regeneration, to provide an unknown manner of assistance to the Doctor. (DW: Planet of the Spiders)

While regenerating into his next incarnation, the Doctor once again saw the Watcher. (BFA: Circular Time)

Behind the scenes

 * In the novelisation of Logopolis, the fact that the Watcher was the Doctor was indirectly alluded to during the TARDIS scenes where Nyssa and Adric were being taken away from Logopolis by the Watcher, allegedly at the Doctor's request. While the Watcher was never heard to speak onscreen, the novelisation suggests that Adric and Nyssa could hear him, possibly by telepathy. Both of them find the voice familiar but are unsure why they recognize it.
 * The nature of the Watcher's conversations with the Doctor and Adric was never revealed. Logopolis suggests that the Doctor was made aware of his impending regeneration due to his statement "the moment has been prepared for." The knowledge passed to Adric is never revealed, although after the transformation, Adric does show an unexpected knowledge of regeneration in Castrovalva.
 * Several other "partial Doctors" have appeared in the history of the series, most notably an evil manifestation, the Valeyard.
 * The Watcher- known as the Observer- of the Doctor's old friend Rallon appeared in Divided Loyalties, merging with the Celestial Toymaker- who had possessed Rallon's body for his own- after Rallon's death to keep the Toymaker in check in future, the transition from Rallon to his Watcher causing the Toymaker's personality to change as though he himself had regenerated.