Following reports of gruesome, cannibalistic murders in the forest, the Raccoon City Police Department dispatches its elite (Special Tactics and Rescue Squad) Bravo Team to investigate. When Bravo Team disappears after their helicopter crashes under suspicious circumstances, Alpha Team —led by Captain Albert Wesker and featuring protagonists Chris Redfield and Jill Valentine —is sent to find them. Into the Spencer Mansion

Inside the mansion, players explore a labyrinth of traps and puzzles while fighting various bio-organic weapons (B.O.W.s), including zombies and giant mutated animals like the snake and the shark Neptune . Through discovered documents, they learn:

S.T.A.R.S. members were intentionally lured to the mansion as "combat data" test subjects. The team discovers that their own leader, Albert Wesker , is a double agent working for Umbrella. The Climax

The mansion serves as a cover for a secret underground laboratory operated by the Umbrella Corporation , a pharmaceutical giant that created the mutagenic T-Virus .