A group of elite operatives from the Bioterrorism Security Assessment Alliance (BSAA) is dispatched to an isolated island after receiving intelligence about a new bioweapon threat. Upon arrival, they find the once-bustling corporate research facility eerily deserted. The operatives, led by Chris Redfield and his partner Jill Valentine, begin to uncover the dark secrets behind the island's abandonment. Signs of chaos are everywhere, hinting at a violent struggle against something monstrous. Evidence points to the involvement of the sinister pharmaceutical company, Umbrella Corporation, known for its role in the global bioterrorism incidents involving the devastating T-virus. As they delve deeper into the facility, the BSAA operatives encounter the remnants of grotesque experiments and a series of cryptic messages left behind by the researchers.

The team soon realizes they are not alone; the island is crawling with the outcomes of Umbrella’s experiments: mutated creatures and zombies that are the result of the new virus strain. The operatives must use their combat skills and quick thinking to survive the relentless attacks. Their mission becomes twofold: stop the threat from spreading and escape the island before they fall victim to the horrors that have been unleashed. As they fight their way through, Chris and Jill uncover potential leads on the origins and purpose of the new viral outbreak, which appear to be linked to a mysterious figure with deep ties to the Umbrella Corporation and past bioterrorism events.