Lucy Saxon

Lucy Saxon was the wife of "Harold Saxon," in actuality the Master. Initially having a happy marriage with the Time Lord, she displayed a sadistic streak and an appreciation for his morality and sense of priority. However, she lost this bond when over the course of "The Year That Never Was" he became abusive and uncaring, revealing to her that she was simply a pawn in his bid for power. Feeling disillusioned and hopeless, a void of despair formed in her, causing her to kill him in an act of cold-blooded vengeance, becoming the first individual to successfully end his life.

With Harold Saxon
After encountering the Master and sharing a trip with him to the end of the universe, Lucy became his partner, appearing beside him for the press and photos. Following the Master's appointment as Prime Minister, Lucy was interviewed by Vivien Rook, who tried to convince Lucy that "Harold Saxon" was a false identity, and that whoever he was, he was putting Lucy as well as everyone else in danger. When the Master appeared through a back door, Vivien tried to cover up what she had stated about him, but discovered that Lucy was well aware of her knowledge, and was killed by a Toclafane before she could leave. (TV: The Sound of Drums)

On the day of the Toclafane invasion, Lucy appeared eager for the fulfilment of the Master's true intent. When the Toclafane appeared and killed American President Arthur Coleman Winters, she showed no signs of fear or alarm and remained calm throughout the entire duration of the events. She joined the Master on the bridge when the sky above the Valiant ripped open and the Doctor was aged, seemingly enjoying the sight of the Toclafane flying down and killing one tenth of the human race. (TV: The Sound of Drums)

The Year That Never Was
Over the year of the Master's reign, Lucy became cold towards him due to abuse she received at his hands, prompting her to join in when the world started to chant the word "Doctor." When the Master, realising his plan had failed, tried to escape, she witnessed Francine Jones raise a gun in his direction, and when the Doctor and Jack Harkness managed stopped her, unseen, she took the gun and shot him, wounding him fatally. Jack managed to disarm her, leaving her motionless, looking on with a cold, emotionless stare at the man who had broken her. After she witnessed the Master refuse to regenerate from the gunshot wound when he realised that the Doctor would keep him permanently confined to his TARDIS, (TV: Last of the Time Lords) she was arrested for his murder. Her trial was held in secret and without a jury, and, found guilty, she was sent to Broadfell Prison. (TV: The End of Time)

Imprisonment and revenge
On Christmas Eve night, 2009, Lucy was released from her cell by her prison's new Governor, and brought to the basement, where a group of the Master's loyal servants was implementing a ritual to restore him to life. One element necessary to the ritual was the Master's bio-metric imprint, something that could be extracted from her lips due to the many times that he had kissed her. To her horror, the ritual succeeded, and the partially-restored Master began draining his servants of their lifeforce. Before the Master's body was completely restored, Lucy revealed to her former husband that she had long been aware of the ritual, and had had her father's scientists develop an opposite to one of the life-restoring potions used in it. Given the potion by one of the guards, she hurled it at the Master, creating an explosion that destroyed the prison and herself. (TV: The End of Time)

Personality
At first, Lucy Saxon was a faithful wife to the Master and seemed to initially share an affectionate relationship with him, nicknaming him "Harry." When the Master took over the Earth, Lucy stood by him loyally, seeming neither shocked nor frightened by her husband's actions. Lucy usually kept her feelings to herself and showed little emotion when the Master ordered the Toclafane to murder one tenth of the human race. Nevertheless, she did apologise to Vivien Rook just before she was murdered by the Toclafane. (TV: The Sound of Drums)

Lucy explained that when the Master took her to the end of the universe she became aware of the futility of life, believing it to be meaningless. During "the year that never was", her relationship with the Time Lord deteriorated, and he became physically abusive, causing Lucy to lose her feelings for him. As the year progressed, she gained a haunted look and became far less at ease, so much so that, after he was defeated, Lucy took her chance and shot him. (TV: Last of the Time Lords)

Vivien Rook referred to Lucy as being from a good family, but claimed that she was not especially bright and essentially harmless, (TV: The Sound of Drums) statements she later echoed, stating that, although she was not especially bright, her family had contacts. (TV: The End of Time) However, her "harmlessness" was lost in the year that never was, allowing her to shoot the Master after he was defeated (TV: Last of the Time Lords) and to sabotage his resurrection. (TV: The End of Time)