Lucie Miller

Lucie Miller was a companion of the Doctor.

Biography
A strong-willed Northern lass, Lucie was initially an unwilling passenger in the Doctor's TARDIS, having been placed with the Doctor as part of a "Time Lord witness protection programme." Lucie told the Doctor that the Time Lords had placed her in his care because she had seen something important; she didn't know what. Her initial attitude towards the Doctor is disdainful, but she recognizes that he's "about saving worlds". (BBCR/BFA: Blood of the Daleks)

Lucie unexpectedly encountered her 'Auntie Pat', Patricia Ryder, the drummer from a band called Methylated Spirits, in 1974. As this is over a decade before Lucie is born, Pat is sceptical, but grows to like her. Lucie's mother is named Mary. (BBCR/BFA: Horror of Glam Rock)

After some time with the Doctor the truth is revealed; the Time Lords learns that the Celestial Intervention Agency have been tracking a woman who would be a future dictator within Europe, and alter her past to prevent this. When Lucie applies for a job which is part of another CIA plot, the primary faction of Time Lords place her with the Doctor to protect her from the effects of multiple exposure to CIA equipment. However in reality, a woman named Karen, who had been interviewed on the same day as Lucie for the job, is the actual future dictator, and the Time Lords have either been tricked by the CIA or simply made a mistake. (BBCR/BFA: Human Resources)

Lucie has a morbid fear of crocodiles. (BFA: The Skull of Sobek) She and the Doctor bumped into Karen and the Headhunter in 19th century Sweden, and stopped their plan of destroying a pocket universe. (BFA: Grand Theft Cosmos)

Lucie met her Auntie Pat again, this time in 1984. Pat was running a hotel in the Lake District with her husband, Trevor. This confused Lucie as she knew nothing of her Uncle Trevor. It was revealed that Trevor was in fact a rehabilitated Zygon, and was being pursued by his former colleagues who kidnapped Lucie and created a copy of her. These Zygons killed Pat but were defeated by Trevor and the Doctor. The Doctor told Lucie of Pat's death and the Web of Time, reasoning how Pat could die but Lucie could still have met her. Unknown to Lucie, the Doctor found Trevor, who had survived the explosion that defeated the Zygons, and Trevor shifted his shape into that of Pat, vowing to remain as her and live her life for her. The Doctor promised not to tell Lucie that the Auntie Pat she knew was never in fact her. (BFA: The Zygon Who Fell to Earth)

When defeating the resurrected Morbius on Karn, the Doctor fell from a balcony on Morbius' palace. Lucie assumed he would be just underneath the balcony clinging for his life. She was devastated when she found there was no sign of him. She refused the Time Lords' offer of removing her memories of the Doctor and her travels and simply requested to be returned home to Blackpool. Some time later, in the middle of the night, Lucie was confronted at her home by an armed Headhunter. It is unknown if she survived the encounter. (BFA: The Vengeance of Morbius)

On her final Adventure Death in Blackpool she gets run over in Blackpool 2008 (after she nearly runs into an earlier self) on Christmas Eve and she goes through an out of body experience.Whilst being tormented by a Zygon she discovers the truth of Auntie Pat and the lie that she and the Doctor shared about what happened in The Zygon Who Fell to Earth.

This shocks Lucie right to her core and the bonds of trust that Lucie and the Doctor had shared broke.When the Doctor caught up with her on Blackpool beach she said her goodbyes and that she would keep the memories of her time with the Doctor special.

Since there is an earlier Lucie Miller at her house at Christmas.She said she would backpack across europe until the summer when the earlier Lucie goes with the Doctor(or gets kidnapped by the Headhunter at the beggining of series 3).

Behind The Scenes
Sheridan Smith revealed that Death in Blackpool will be her last story as Lucie Miller.