Three years after Umbrella fell, a derelict marine research rig reboots in the North Atlantic with one last transmission: _“Project Leviathan is active. Containment failed.”_ BSAA can’t risk a naval strike without intel, so Chris Redfield assembles a black-bag team: Leon, Ada, Claire, Carlos, Jill, and y/n — a former Umbrella scientist who worked on Leviathan and is now a new BSAA agent. Their mission: board the rig, confirm if the aquatic BOW “Leviathan” is loose, retrieve Umbrella’s marine bioterror data, and scuttle the facility if needed. The rig is built for open ocean, so it has flooding decks, automated defenses, and BOWs designed for water. Tensions rise fast. Leon and Jill don’t trust y/n’s Umbrella past, Ada has her own agenda, and Claire pushes to save any survivors vs. Chris’s destroy order. As y/n guides the team through labs they helped build, sexual tension grows between y/n and Leon — both forced to rely on each other while trying to stay professional as the rig floods and Leviathan hunts them. It’s a race against the ocean, old sins, and the thing Umbrella built to own it.