After the S.T.A.R.S. investigation during the Mansion Incident, news of Umbrella's illegal biological experiments was made public. In what would become known as the "Umbrella Incident" (アンブレラ事件), the company subsequently collapsed and its facilities in Raccoon City were carefully guarded by the police department. Two months later, a mysterious skin disease begins to spread around Raccoon City, with those dying from it rising as zombies. The Raccoon City Police Department, despite its modern riot defenses, soon falls to the infection but not without attempts to seal them behind shutters.
Leon's Scenario
Rookie police officer Leon S. Kennedy is one of the few remaining officers in the city. Leon finds an Umbrella researcher, Ada Wong, who was trapped in a crashed and burning police van in Outside B (外B,SOTO B?); he saves her with the fire extinguisher. Leon later sees Sherry Birkin crawl down a drain from the vehicle workship ("CHIKA CYUU B"). In the next room, an underground parking lot ("CHIKA CYUU A"), Leon finds Ada on her own and scolds her for leaving Marvin. She explains that she heard a noise and left Marvin to go investigate. The noise is revealed to have come from a crashed Umbrella van, and two gorilla B.O.W.s break out. Leon calls Ada to hide in a patrol car as he fights them.
The trio climb down the sewers. Exploring the sewers, Leon narrowly escapes a torrent of running water and encounters various mutations on the way.
After losing track of Ada, Leon and Marvin exit into the Factory compound's SITE A (敷地A,SHIKICHI A?), where they find the entire remaining police force - the large investigation team assigned to the factory - has been killed in a battle. Heading into a Warehouse (倉庫,SOUKO?), Leon fights the mutated William Birkin, who was recently knocked out by Elza. The three take the elevator down to the lab, and Marvin gets injured in the process. Ada and Leon take Marvin to the GUARDHOUSE to recover. There, she reveals that she is in fact an Umbrella researcher, but tells Leon he doesn't have time to worry about that; Marvin is at risk of dying if not treated immediately. Ada conscripts Leon to reactivate the lab's power and take the delicate vial of the viral strain to a machine which will create an appropriate vaccine. When he has cured Marvin, Ada will wait for the two of them in the shelters below, though makes no guarantee they will survive down there.
Leon would fight a further mutated William in the labs who smacks a man-spider to it's death during a scene. Leon would fight a further mutated William once again in the train power room and in the umbrella train, Annette being with Leon at the time.
Elza's Scenario
Elza Walker, a college student, returns back to Raccoon City from summer vacation. Stumbling upon the infestation while riding her motorcycle, she crashes into the near-emptied police department. Looking for help, she finds John and Roy, the latter of whom is injured and close to transforming into a zombie; at some point John has to kill Roy in Office B, and chooses to stay behind to mourn his friend. Elza soon is introduced to Sherry Birkin in a vehicle workshop ("CHIKA CYUU B"), but is initially unable to reach her due to a locked door. She also meets Brian Irons, the chief of police; the injured man dies soon after hoping that his men are safe. Traveling to the rooftop, Elza is saved from a murder of crows by John. The two push down some crates and use them to cushion their fall as they land in Outside A (外A,SOTO A?). John tells Elza he saw a girl escape into the sewers and the two go down to look for her.
The three, united, climb up a ladder and reach the factory's exterior, SITE A (敷地A,SHIKICHI A?), where they find that the city's police force has been annihilated. Sherry leads them inside the factory by crawling through a vent and opening the Corridor (廊下,ROUKA?) from the inside. As Elza operates a panel in the Warehouse (倉庫,SOUKO?) the infected William Birkin breaks out of a nearby elevator and fights Elza; when he is knocked out, the three take the elevator down to the laboratory.
