Mirror's Edge takes place in an unnamed city where a totalitarian regime monitors its citizens through invasive surveillance, tracking all forms of electronic communication in order to reduce crime and quell any challenge to its power.An upcoming mayoral election seeks to retain Mayor Callaghan in power to keep the government's control on the city, though a new favoured candidate Robert Pope promises to bring change. The Eurasian protagonist, Faith Connors, is a "Runner", a person trained in parkour, to stay out of sight and to use rooftops and other means to help deliver physical messages between revolutionary groups within the city. Faith along with another Runner, Celeste, were both trained by Mercury who also provides radio support for the two.
Faith receives a call for help from her sister Kate, a police officer, at the offices of Pope, and finds that Pope has been murdered, clutching a piece of paper with the name "Icarus" on it. Kate tells Faith to find out more and to report anything to her superior, Lt. Miller. Faith finds a former Runner named Jacknife who identifies that Pope's head of security, a former wrestler named Ropeburn, may have more information, but does not divulge any more. Faith reports this to Lt. Miller, who arranges a meeting with Ropeburn; Faith attempts to listen in, but Ropeburn discovers her and attempts to kill her. Faith gains the upper hand, and hangs him over a rooftop, attempting to gain information, but before she can, Ropeburn is killed by an unknown assassin. Faith gives chase to the assassin, discovering the assassin works for a private security firm that the city relies on heavily for its armed forces, and that the firm is training its own form of Runners in order to capture or kill the other Runners in the city. She regains the assassin's trail to a tanker and is able to corner the assassin, finding that it is Celeste. Celeste states that she has changed sides due to "Project Icarus" to avoid being constantly hunted by security forces and to be able to live her life. Fearing that she will be arrested if she is caught with Faith, Celeste escapes from Faith and disappears.
Mercury tells Faith that Kate has been convicted of Pope's murder, and arranges a spot where Faith can ambush the convoy that is taking her to prison. Faith is able to successfully free Kate, telling her to flee to the lair where Mercury is waiting while she lures the police away. After avoiding her chasers, Faith returns to the lair to find it has been attacked, Kate having gone missing and Mercury near death. Mercury is able to tell Faith that Kate has been taken to the Shard, a skyscraper that is home to Mayor Callaghan as well as the city's centralized surveillance databases. With the help of Lt. Miller, who feels Faith is the city's best hope for change, Faith is able to make her way to the server rooms and destroy the servers, unlocking access to the roof. However, during this, Miller is suddenly cut off, and a shot is heard. There, she finds that Kate is being held at gunpoint by Jacknife. Jacknife explains that Project Icarus is a plan created by Callaghan to eliminate all the Runners in the city and to stop the uncontrolled flow of information, and that unlike Celeste, who took part in it only to stay alive, Jacknife was involved in it all along as a driving force. Jacknife attempts to escape with Kate in a waiting helicopter, but Faith follows and grabs onto it; she is able to jump into the helicopter and send Jacknife plummeting to his death. As he falls, stray bullets from his gun hit the helicopter and cause it to spin out of control. Faith helps Kate to safely jump to the nearby roof as the helicopter crashes below. The two hug and the camera begins to zoom back to show that they are atop a skyscraper overlooking an entire city. During the game's end credits, an announcement states that both Faith and Kate are now wanted criminals but have gone missing, while urging the citizens of the city to avoid electronic communications until the city can repair the faults with the Shard's servers. The announcement also emphasizes that further questions are now being raised about the Runners, suggesting that Project Icarus is well in motion.
Mirror's Edge aims to "convey the strain and physical contact with the environment", according to senior producer Owen O'Brien, and to instill a freedom of movement not yet seen in the first-person genre.This is achieved not only with the exercise of free running, but also by tying camera movement more closely with character movement, such that the rate at which the camera bobs up and down increases as Faith builds up speed while running and the camera spins when she rolls.
Also, the arms, legs, and even torso at times are prominent and their visibility is used to convey movement and momentum, such that Faith's arms pump and the length of her steps increase with her gait, and her legs cycle and arms flail during long jumps.
With such a heavy foc