Throughout the course of the game you will interact or hear from many different characters. Some are allies and others are enemies but all are there to progress the game. Here is a list of all the characters in Mirror's Edge.
Faith is a Runner, a person used to transmit messages while evading government surveillance. The game's story follows Faith and her struggle to prevent her sister (Kate) from false imprisonment after she was framed by the corrupt government for the murder of the leader of an opposing political party.
Her mother was killed while her parents were protesting in the November Riots against the government's implementations of a "Big Brother" life over the people of the city. At the age of 16, she ran away from home, blaming her father for her mother's death. Living on the streets, Mercury caught her trying to break into his apartment, where he then decided to train and hire Faith as a Runner. Faith was taught not to rely on modern forms of communication, partially because the ruthless police state is able to hack into any private communications. As Faith attempts to rescue her sister, while running messages for those who oppose the "New City", she gets caught up in a series of events which lead to her being pursued by the totalitarian government.
Mercury is a mysterious character who acts as Faith's guide, or tracker as they are called in the game. Mercury will help Faith in her attempt to outwit and overcome the many government agents that are out to eliminate her. Mercury is also the person who, after catching her breaking into his apartment, trained Faith as a Runner. Mercury is only seen in animated cartoon trailers and between-chapter cutscenes of Mirror's Edge. Throughout Mirror's Edge, Faith and Celeste refer to him as "Merc". In the cut scene in which Faith discovers the truth behind Project Icarus, Merc is listed as a third tier tracker who lives in the Willshire district.In chapter 9, Merc is killed by the cops. His last words to Faith were, "Just dont let them win.".
Celeste, like Faith, is a Runner. She is Faith's ally and friend and often helps Faith on missions. She is commonly known as 'Cel'. She helped Faith train to continue being a Runner after Faith injures herself. Celeste is seen in the Mirror's Edge training stage with Faith and is also seen helping Faith with a mission.However,in mission 8,Faith finds out that Cel is a cop,and was working with Ropeburn to kill Pope. It is unknown whether she was killed or not.
Kate is Faith's sister, who is a member of the CPF (City Protection Force) for the duration of the game and was framed for killing Robert Pope, a mayoral candidate. She was then taken into confinement. She appears in the game in chapters 1, 8, and 9.
Another fellow runner, he assists in Faiths escape in Chapter 1 and is only seen there. Later he assists Faith with a supply drop in Chapter 8 and can also be seen here in-game. In the cut scene in which Faith discovers the Icarus, you can see Kreeg listed as a second tier runner who lives in the New Eden district.
Another Runner manager/tracker. His role is similar to Merc's and probably can only be seen in the intro. It's mentioned that he gives Celeste jobs. In the cut scene in which Faith discovers the truth about Project Icarus, Drake is listed as a third tier tracker and his picture can be seen.
A former Runner who Faith does not seem to like. Faith sees him only for information regarding the Pope case. It is implied through out the game that he and Faith had some sort of relationship in the past; romantic or not, it is never elaborated upon. Mercury states that Jacknife used to be a decent Runner.
An ex wrestler employed as Robert Pope's head of security and the owner of Z Burfield shipping industries. He is a brutal musclar thug who apparently has a bad history of wrestling.
Kate's CPF superior. He is apparently the only cop Faith can trust. Through most of the beginning of the game, Faith mainly tries to earn his trust, and in the last level, The Shard, Lt. Miller assists Faith in getting to Kate. It is unknown what happened to him however, as in the Shard level, when Lt. Miller is telling you about the surveillence units, his voice is cut off, and you don't hear from him, or see him after that.
An unseen Antagonist. She is the person responsible for the totalitarian government of the city.
"Blues" is a generic slang term used by Runners to describe any form of law enforcement used in the city. Normally, Blues leave Runners alone, but Pirandello Kruger, a company secretly training law security personnel to hunt runners, has ordered it's forces to shoot any runner they see, and to pursue them for as long as possible. Blues come in various outfits, from standard police officers, to S.W.A.T. soldiers, and each type sports a different type of weaponry, from pistols to shotguns, to assault rifles. They are the primary antagonist throughout the game.