Controller (Bad Wolf)
Blind and connected to Satellite Five feeds at the age of five by dozens of cables, the Controller acted as the eyes and ears of the Daleks. Aided by programmers, she constantly monitored the transmissions that flowed through her. (DW: Bad Wolf) Essentially, she served a similar function to the Editor and the Jagrafess a century before, who also had occupied Floor 500 of the satellite, though the Controller had less say over her actions. (DW: The Long Game)
Nevertheless, the Controller loathed and plotted against the Daleks, ensuring that the Doctor and his companions would appear in game shows on Satellite Five (now called the Game Station), which the Daleks ignored. She waited until a rare solar flares would temporarily disrupt communications between the Dalek fleet and the Daleks could not monitor her thoughts, enabling her to warn the Ninth Doctor of the enemy "waiting in the dark" and pass on to him the co-ordinates of Rose Tyler, which would enable him to rescue her, though she did not at that point reveal to the Doctor and his allies the identity of her "masters".
She told him part of the coordinates (5.6.1.434. sigma 777) before she was transmatted to the main Dalek saucer and the Daleks quickly exterminated her. (DW: Bad Wolf)
When Davros makes the comment How many more have died in your name to the Doctor. The Controller is among these people he was unable to save. Hence she appears in a flashback of people that the Doctor was unable to save. (DW: Journey's End)
- The Daleks also employed a Controller as their collaborator on an alternative Earth, which they had conquered. (DW: Day of the Daleks)