Resident Evil

On July 24, 1998, the Bravo Team of the Raccoon City Special Tactics and Rescue Service (S.T.A.R.S.) is sent out into the surrounding Arklay forest to investigate a recent string of cannibalistic murders. When contact with them is lost, Alpha Team is sent out to investigate – consisting of Chris Redfield, Jill Valentine, Barry Burton, Joseph Frost, Brad Vickers, and captain Albert Wesker. They discover Bravo Team's helicopter crashed in the forest, with pilot Kevin Dooley dead at the scene. Alpha Team continue to explore the surrounding forest, but are suddenly attacked by a pack of ravenous Dobermanns. Joseph is mauled to death, while Brad flees in their helicopter – the survivors flee from their pursuers, eventually taking shelter in a mysterious mansion.
One member of Alpha Team (Barry in Chris' story, Chris in Jill's story) is separated and does not make it inside – the player character splits off from the others to investigate noises coming from the west wing, but discover Bravo Team member Kenneth J. Sullivan being eaten by a zombie. When Wesker mysteriously vanishes (alongside Jill in Chris' story), the player is left to explore the mansion alone and attempt to find their allies. As they explore, they find that Bravo Team has been massacred – Forest Speyer was pecked to death by infected crows, while Richard Aiken dies from venom poisoning after being bitten by Yawn, a giant mutated snake, and captain Enrico Marini is shot dead in the torso by an unseen person just after revealing that there is a mole in S.T.A.R.S.. The only Bravo Team survivor, field medic Rebecca Chambers, is rescued by Chris.
The player eventually comes to discover that the mansion was a research facility of Umbrella, a pharmaceutical corporation that was secretly producing Bio Organic Weapons (B.O.W.s) for unknown purposes. The cannibalistic murders were caused by an outbreak of the "Tyrant Virus" (t-Virus for short), a virulent agent capable of turning any species it infects into flesh-eating zombies. At an underground laboratory beneath the mansion, the player discovers that Wesker is the mole, being an employee of Umbrella placed in S.T.A.R.S. to keep an eye on their operations; He also blackmailed Barry into helping him under the threat of Umbrella killing his family, but if Barry survives, he turns on Wesker upon learning that he was bluffing as he betrayed Umbrella for his personal interests.
Wesker releases the prototype Tyrant, a B.O.W. super soldier which he calls the ultimate bio-weapon, in order to demonstrate its potential after the survivors mock it as a failure, but his plan backfires as it kills him first before focusing on the player, who defeats it. Optionally, the player can save the other playable character from a holding cell if they collected a set of MO disks scattered around the mansion, and, if their partner survived (Barry for Jill and Rebecca for Chris), the self-destruct sequence for the mansion will be activated. The player and anyone they saved escape to a helipad where they fire a flare to signal Brad, who is still flying his helicopter looking for them. The survivors are ambushed by the Tyrant, and battle it until Brad drops a rocket launcher for the player to finally destroy it. All remaining survivors of the incident then fly out of the mansion. The ending varies depending on whether the partner survived and/or the supporting character was freed. If the partner did not survive, the self-destruct sequence is not activated and the mansion does not explode, while the Tyrant is now loose in the wilderness. If the supporting character was left in their cell, they are presumed dead. Canonically, all four protagonists (Chris, Jill, Barry, and Rebecca) survive and the mansion is destroyed.