Resident Evil Zero begins in July 1998, one day before the events in Resident Evil, following a bizarre succession of murders in the Arklay Mountains located just outside the small mid-western town of Raccoon City. Because of the unusual nature of the murders, the Raccoon City Police Department sends six members of the elite S.T.A.R.S. (Special Tactics And Rescue Squad) Bravo Team including Rebecca, a young women on her first mission, to investigate.
As the team sets out in their helicopter, they spot a mysterious train stopped in the woods. Then suddenly, for some unknown reason the engine in the chopper stalls. As the chopper begins to fall into the woods the team sees a burning wagon in the distance. After the crash, the team decides to split up to investigate the two sightings. One team sets out to investigate the wagon and the other team, including Rebecca, to investigate the train. As Rebecca enters the mysterious train, the horror and the battle to survive Resident Evil Zero begins.
Rebecca encounters an escaped convict named Billy Coen. She soons learns that she must put her duty aside and team up with Billy to survive. With the addition of the new zapping system in Zero, you take control of both players and use each of their strengths to survive.