In 2003, Umbrella was facing total dissolution, but the corporation had one final card yet to play. The Caucasus plant housed all of their research data and corporate records and had been tasked with the development of the T-A.L.O.S. Project, which was to be the pinnacle of bio-weapon engineering.
In February of that year, the Caucasus plant was raided by a group of anti-Umbrella activists led by ex-S.T.A.R.S. members Chris Redfield and Jill Valentine, who had received an anonymous tip-off regarding the existence of T-A.L.O.S.. Unknown to them, it was their old captain turned enemy Albert Wesker who provided the intel and he had decided to make his own infiltration of the Caucasus lab whilst Chris and Jill's force dealt with T-A.L.O.S. and the many other B.O.W.'s within the facility. He entered the factory first and triggered a T-virus leak that resulted in the infection of the facility staff, making the situation all the more difficult for his former subordinates. While Chris and Jill dealt with T-A.L.O.S., Wesker made his way to the control centre in order to steal all of Umbrella's data from the central computer hub, the U.M.F. -013, and to confront the head of the facility Sergei Vladimir. After eliminating Sergei's Ivan bodyguards, Wesker fought Sergei in the factory's control room. Sergei injected himself with a T-virus strain and mutated into a Tyrant-style monster, but even this did not help him against Wesker, whose own superhuman abilities far surpassed his. Sergei was killed by Wesker while Chris and Jill destroyed the T-A.L.O.S..
With the destruction of T-A.L.O.S. and Wesker's acquisition of the U.M.F. -013, the Caucasus plant was sterilized and shut down. Mere days later, Wesker would make an an anonymous contribution to the US Supreme Court, providing them with all the evidence needed to close the Raccoon Trials and destroy Umbrella for good. Of course, Wesker only did it for personal gain, and now that he had obtained all of Umbrella's research material and records, he was brought one step closer to gaining absolute power.
Below is a complete list of all the creatures encountered in the Caucasus laboratory.
- Zombies - When Wesker entered the facility, he set off a device that led to a T-virus outbreak which infected most of the plant's staff.
- Zombie dogs - Umbrella guard dogs infected with the T-virus.
- Web Spinners - Giant mutant tarantulas.
- Infected bats - A number of bats, including a giant specimen, were encountered by Wesker in one of the plant silos.
- Chimera - Experimental B.O.W.'s that had been discontinued following the loss of the Arklay Laboratory, but the Caucasus lab had restarted the programme at some point.
- Eliminators - Another early B.O.W. concept that had been re-initiated by the Caucasus plant.
- MA-121 Hunter "α" - Regularly produced bio-weapons that Umbrella began trading on the black market.
- Crimson Heads - Zombies undergone a V-ACT mutation, becoming stronger and faster.
- Lickers - Human-based B.O.W.'s that had become popular on the black market.
- Ivan T-Types - A pair of modified T-103's that acted as Sergei Vladimir's bodyguards.
- T-A.L.O.S. - Umbrella's ultimate Tyrant-class B.O.W., equipped with cybernetic armour, advanced weaponry, and controlled directly by the Red Queen AI.
- Sergei Vladimir - Head of the Caucasus plant and commander of Umbrella's paramilitary forces. He injected himself with the T-virus in order to confront Wesker, but this proved to be insufficient and he was defeated.