Synopsis

One day before the incident in the mansion (events of Resident Evil 1), a train carrying Umbrella employees gets attacked by infected leeches and the train stops.  Later on, the S.T.A.R.S. Bravo Team of Raccoon City goes into the nearby forest of the Arklay Mountains via helicopter, but something causes them to crash down in the middle of nowhere.  The team's captain, Enrico Marini finds a flipped over transporter for prisoners and a document indicating that escape convict, Billy Coen, is somewhere in the area.  The team split up to go locate him. 

Rebecca Chambers finds the Eclipse Express train stopped on the tracks in the middle of the forest.  She enters to investigate.  Inside, she discovers that the passengers have been turned into mutant zombies and have a thirst for blood.  She soon discovers the prisoner, Billy, who's one arm is still wearing a handcuff.  They team up and explore the train, which for some reason, starts up on its own. 

Battling zombies, Cerberus dogs, leeches and even a giant scorpion, the duo end up crashing into the abandoned Umbrella Training Facility, they explore around, looking for a way to survive the biohazard nightmare.