Mia Nolan is a main character in Crocodile. She is portrayed by Andrea Riseborough.
When she was a teenager, Mia left a party with then-boyfriend Rob. Both were drunk and, as they went down the road, they hit a bicyclist who died on impact. In order to avoid going to jail, Rob forces Mia to help him ditch the body and cover it up. Fiftyeen years later, Mia is now a respected architect with a family. After giving a speech at an architect conference, Mia is visited in her hotel room by Rob, who has come to discuss the accident and how he was going to send an anonymous letter confessing to the wife of the dead bicyclist of how they accidentally killed him. Mia, in a fit of terror and possessing the knowledge that she would be exposed alongside him if he sent that letter, furiously struggles with Rob until she eventually strangles him to death. Looking out the window, she notices a man being hit by a pizza delivery truck. Mia buys a porn movie on her TV to drown out any noise made as she forces Rob's body into a food tray and slowly wheels him out of the hotel, into the parking lot and into her car, at which point she drives him to a construction point and dumps his body in a sewer. The next morning, she checks out of the hotel and flies back home.
A few days later, she is visited by Shazia Akhand, an insurance agent who is investigating the collision between the man and the pizza truck that Mia observed earlier. Using a Recaller, a machine that can access engrams (memories of what happened), she digs deep and finds more than she wanted to, from the death of the bicyclist to Mia killing Rob all the while with static in the background. Shazia, terrified, attempts to remain calm and leave, but is kidnapped by Mia when her car fails to start. Mia, after interrogating Shazia and deciding that she would immediately tell the police, bludgeons Shazia to death and leaves her body in a remote shack. Using Shazia's car, Mia drives to her home and kills her husband in the bathtub with a hammer. On the way down, Mia is about to leave when she notices a baby in the corner. She walks towards it, crying and mortified. The scene then cuts to Mia going to see her son's school play, Bugsy Malone.
Back at Shazia's house, police have arrived and are disgusted that someone would kill a baby, saying that the baby had been blind. The police, having used a Recaller on Shazia's pet gerbil to find the killer, arrive at the school play to arrest Mia. The episode ends with Mia applauding the school play with tears streaming down her face.