The Spencer Mansion, a foreboding estate located in the forests northwest of Raccoon City, was believed by the public to have been left abandoned shortly after its construction. In truth, however, the mansion was merely a cover to hide the existence of an underground genetics laboratory controlled by the pharmaceutical giant, Umbrella Inc. In the laboratory, Umbrella had secretly been developing biological weapons and were experimenting with a man-made mutagenic pathogen known as the Tyrant virus (more commonly referred to as T-virus).
In the spring of 1998, an incident occurred within the laboratory and the T-virus was scattered inside the facility, infecting many of the staff and residents and turning them into shambling, flesh-hungry zombies. Those not infected by the initial outbreak would find themselves trapped within the locked-down mansion, falling prey to their undead former colleagues, the mansion's many traps or the other mutations created by the virus. Within a matter of days, everyone in the mansion had either been killed or infected and the T-virus would begin to slowly spread through Raccoon Forest, infecting other indigenous creatures.
In June 1998, Raccoon City began to experience a sudden increase in violent crime. Citizens were being attacked and murdered by unidentified persons on the outskirts of the nearby forest. According to coroner reports, the victims were all partially eaten. Some townspeople also suffered fatal attacks from wild animals that could not be identified. After several weeks with over ten victims, the Raccoon Police Department mobilised its elite Special Tactics & Rescue Squad (S.T.A.R.S.) to investigate the cannibal killings and bring the culprits to justice.
On July 23rd, the S.T.A.R.S. Bravo Team were dispatched to investigate. However, their helicopter suffered an engine failure, forcing them to make an emergency landing. Shortly after landing, the team found themselves under attack by the mutated creatures roaming the forest. Unprepared for this kind of threat, they became scattered. They would eventually find themselves heading toward the Spencer mansion, but they would find that the house offered no shelter from the nightmare they had stumbled into.
Rebecca Chambers, Bravo Team's medic, would find herself investigating an abandoned train in an event that coincided with the team's mission.
On July 24th, the S.T.A.R.S. Alpha Team were sent out to find the missing Bravo Team and complete the investigation into the cannibal murder case. The team's chopper landed after discovering Bravo Team's chopper, and the team found the craft to be empty, save for the body of the pilot Kevin Dooley, who had been savagely mauled by an unknown creature.Shortly after landing, the Alpha Team was attacked by a pack of zombie dogs. Joseph Frost was eaten alive by the creatures and the team's chopper pilot Brad Vickers panicked, taking off in the chopper and leaving the others to die. The remaining S.T.A.R.S. - Chris Redfield, Jill Valentine, Barry Burton and the team captain Albert Wesker - fled from the mutant dogs and made their way to the Spencer mansion. After making it to the house, the team split up to search the area. With the mansion being the only structure standing in the forest, this was surely to be the hideout of the supposed cannibal cult responsible for the murders in Raccoon City. Minutes into the search, the S.T.A.R.S. found out that the murders were commited not by people but by zombies. What was once believed to be the stuff of Hollywood horror films was in fact very real and trying to kill them.
The members of Alpha Team battled their way through the terrors of the mansion, discovering that most of Bravo Team were dead and that a more insidious force was at work here. From documents discovered throughout the mansion and the adjacent residence, the S.T.A.R.S. learned that the creatures infesting the mansion were products of a man-made virus, with evidence leading to the involvement of the Umbrella Corporation, the pharmaceutical enterprise that provided most of the jobs and services in Raccoon City. After finding all of the necessary keys and trinkets around the mansion and residence, the S.T.A.R.S. uncovered the entrance to Umbrella's secret bio-weapons laboratory.Within the laboratory was evidence that indicated that Wesker, the S.T.A.R.S. captain, was working with Umbrella. During the investigation of the catacombs beneath the residence, Chris and Jill had found Bravo Team's leader Enrico Marini, who warned them that the S.T.A.R.S. had been set up before he was shot by an assailant hiding in the shadows. The team found Wesker inside the lowest level of the lab, where he revealed his plan to lure the S.T.A.R.S. into the mansion in order for him to gather combat data on the bio-organic weapons that were running loose in the facility. He then activated the ultimate bio-weapon - the Tyrant-002 - which smashed its way out of its stasis tank and attacked. Wesker could not control the creature and it impaled him on its massive claw, then proceeded to attack Chris and Jill. Chris and Jill managed to stop the Tyrant before meeting up again with Barry Burton and the sole surviving Bravo, Rebecca Chambers.
As the surviving S.T.A.R.S. reconvened, an alarm went off and an announcement went out stating that the lab's self-destruct system had been activated. The self-destruct automatically released all locks in the facility, allowing the survivors to make their way to a chopper pad on the roof of the mansion. However, after arriving at the helipad, the team was again attacked by the Tyrant which had now mutated and become even stronger. The team's guns had no effect on the creature and the clock was counting down to the mansion's destruction. The S.T.A.R.S. chopper piloted by Brad Vickers arrived just in time and dropped a rocket launcher on to the helipad, which Chris was able to use to blast the Tyrant to pieces. With the Tyrant dead, the S.T.A.R.S. were able to escape the mansion just before it exploded. They had survived their longest night, but Umbrella had to be made to pay for their crimes.
Following the destruction of Umbrella's Arklay research laboratory, the surviving S.T.A.R.S. attempted to expose Umbrella's activities. Unfortunately, all solid evidence of the incident had been destroyed when the mansion exploded and the chief of the Raccoon City Police had been bought off by Umbrella. Chris Redfield and the other S.T.A.R.S. members were disgraced and forced to leave the RPD, but would continue their efforts to expose the truth to the world.
Unfortunately, not all traces of the T-virus were destroyed along with the mansion. The waters running through the Raccoon Forest had been contaminated and Umbrella continued working on the virus in other facilities within Raccoon City itself. In just six weeks, these factors would contribute to beginning the Raccoon City Disaster that would lead to the exposure of bio-organic weapons to the world, but at the cost of over 100,000 lives.
The following is a list of the monsters encountered by the S.T.A.R.S. during the Mansion Incident.
The following members of S.T.A.R.S. were killed in action during the Mansion Incident.
- Kevin Dooley - Chopper pilot for Bravo Team. Never even left the pilot's seat before he was attacked and killed by zombie dogs.
- Edward Dewey - Bravo Team mechanic and co-pilot. Attacked by zombie dogs and infected with the T-virus. When Rebecca Chambers was investigating the Eclyptic Express train, Edward succumbed to the virus and became a zombie. He was then put down by Rebecca.
- Joseph Frost - Vehicular specialist for Alpha Team. Shortly after Alpha Team landed in Raccoon Forest, Joseph was attacked and eaten alive by a pack of zombie dogs.
- Kenneth Sullivan - Point-man for Bravo Team. He is attacked and killed by a zombie, which Alpha Team discovers feeding on his corpse just seconds later.
- Richard Aiken - Bravo Team's communications expert. His fate depends upon the player; if playing as Chris, Richard will be devoured by a Neptune in the Aqua Ring whilst trying to save Chris. If the player is Jill, Richard will die during the first encounter with Yawn, in which the snake swallows him whole. These deaths will only occur if the player saves Richard with a bottle of serum after he suffers a poisonous snake bite, otherwise he will be killed by the poison.
- Forest Speyer - Bravo Team marksman. While investigating the mansion's second floor east balcony, he is pecked to death by a flock of infected crows. He is reanimated as a zombie and his Alpha Team compatriots are forced to put him down.
- Enrico Marini - Captain of Bravo Team. He manages to last longer than the rest of his men and he discovers that there is a traitor amongst the S.T.A.R.S. working for Umbrella. Before he can reveal the traitor's identity, he is shot from the shadows.
- Albert Wesker - Captain of the S.T.A.R.S. Alpha Team and the traitor Enrico warns of. He is acting on Umbrella's orders to gather B.O.W. combat data and destroy the mansion, removing all evidence that could incriminate the corporation. However, unbeknownst to Umbrella, Wesker is also working toward his own ambitions and intends to desert the company. When cornered in the lab, he activates the Tyrant and the creature attacks him, seemingly killing him. However, just prior to his impalement, Wesker had injected himself with a special viral strain that reanimated him and blessed him with superhuman abilities. He then escaped the mansion and disappeared, assumed dead until encountered again by Chris Redfield during the Rockfort Island Incident.