Riley has been estranged from her mother for a long time. But her mom has just bailed her out of rehab for the umpteenth time. Riding on the subway together, they blame each other for their life's problems. Suddenly, a man turns into a zombie in front of them and begins attacking the other passengers. The subway goes through a tunnel and the lights shut off. Screams and shouts of pain echo throughout the train. Can the mother and daughter team work together and survive the beginning of the zombie apocalypse?