Resident Evil 7: Biohazard is set in mid-2017 somewhere in the southern United States, where there have been reports of „ghosts“ sighted around the bayou of the town, Dulvey. The game proper takes place after the events of Beginning Hour, which ended with the murder of a three-man TV crew by the possibly-infected Baker family members Jack and Mia. It features a new protagonist named Ethan Winters, a civilian who offers fewer combat skills than most previous Resident Evil protagonists. Ethan is searching for his missing wife, Mia, which leads him to a derelict plantation mansion, home of the Baker family.
The game begins with Ethan Winters traveling to Louisiana after having received a request from Mia to find her there, despite the fact that Mia had gone missing three years ago and was presumed dead. When Ethan arrives, he finds a seemingly abandoned farmhouse with Mia imprisoned in the basement. Mia warns him that they must escape before „Daddy“ finds them. Ethan then receives a phone call from a woman named Zoe, who tells him that there is an escape route through the attic. However, as Ethan and Mia make their way up there, Mia suddenly goes berserk and begins attacking Ethan, forcing him to kill her in self-defense. He is then knocked out by Jack Baker, the patriarch of the Baker family.
Meeting the Bakers
Ethan then wakes up to find himself captive and in the company of the Baker family, who consist of Jack, his wife Marguerite, their son Lucas, and an unnamed elderly woman in a wheelchair. The Bakers attempt to force feed him their food (cooked human parts) and begin torturing him until they are distracted by a phone call. Ethan manages to break free from his bonds and tries to find a way to escape the Bakers’ mansion. During this time, he periodically receives helpful advice from Zoe, who reveals herself to be Jack’s daughter.
When a deputy comes to investigate the mansion, Ethan tries to warn him about the Bakers, but the deputy is skeptical of his claims and is killed by Jack. Ethan manages to kill Jack in response, but quickly finds out that Jack and the other Bakers have powerful regenerative abilities, allowing them to heal normally fatal wounds. Ethan must also avoid monstrous creatures that the Bakers have been creating from other people they have kidnapped. Eventually, Ethan has a second showdown with Jack, killing him again and obtaining the key he needs to escape the mansion.
Battling the Bakers
Making his way to the yard, Ethan finds out from Zoe that Mia is still alive, since she has been given the same infection the Bakers have. Zoe informs him that she wants to escape the Bakers as well, but both she and Mia would need to have their infections cured by a special serum first. Ethan heads out to an old house to find the ingredients for the serum, where he is forced to battle and kill Marguerite. Once he retrieves the ingredient, Ethan begins to have strange visions of a young girl.
He then returns to meet with Zoe, but is instead contacted by Lucas, who has captured both Mia and Zoe and is holding them hostage. Lucas forces Ethan to navigate a barn filled with monsters and traps, but Ethan is able to outsmart Lucas, forcing him to flee. He then rescues Mia and Zoe, who is able to manufacture two doses of serum. However, at that moment, a heavily mutated Jack attacks again, and Ethan is forced to use one of the serum doses to kill him permanently. With only one dose of serum left, Ethan must choose whether to cure Mia or Zoe.
If Ethan chooses Zoe, Mia is heartbroken over the choice despite Ethan’s promises to send help. As he and Zoe escape on a boat, Zoe reveals to him that the Bakers were infected due to Mia arriving with a girl named Eveline three years ago, when the wreck of a tanker ship washed ashore. However, they are attacked by Eveline herself, and Zoe is killed while Ethan is knocked out. He has a vision of Jack, now sane, who warns him that Eveline has the power to brainwash anybody she infects, which is how he and his family went insane, and he pleads for Ethan to kill her.
The game then switches to Mia’s perspective, who wakes up on the wrecked ship and searches it for Ethan. Once Ethan is found, the game switches back to his perspective. Mia rescues Ethan and gives him a vial of Eveline’s DNA before Eveline takes control of her. Mia fails to resist due to her feelings of betrayal towards Ethan’s choice to save Zoe. Mia then attacks Ethan, and he is forced to kill her. The plot then merges back at this point. This leads to the alternate/bad ending.
If Ethan chooses Mia, Zoe reluctantly stays behind and gives a bitter farewell to Ethan and Mia. As he and Mia escape on a boat, they come across the tanker ship where they are attacked by Eveline. Ethan is knocked out and he has a vision of Jack, now sane, who warns him that Eveline has the power to brainwash anybody she infects, which is how he and his family went insane, and he pleads for Ethan to kill her.
The game then switches to Mia’s perspective. She wakes up on the wrecked ship and begins searching for Ethan, but keeps receiving visions of Eveline who keeps claiming that Mia is her mother, despite Mia not remembering anything about her. Eventually, Eveline makes Mia watch a video tape to restore her memory. It is revealed that Mia was in fact working for an unnamed corporation that was developing Eveline as a bioweapon. It was her job to oversee Eveline as she was being covertly transported to the United States on board the tanker ship. However, Eveline managed to escape containment and cripple the ship. She then infected Mia in an effort to force her to be her mother. Realizing her role in creating Eveline, Mia rescues Ethan and hands him a vial containing Eveline’s DNA. She manages to resist Eveline’s control long enough to seal Ethan out of the ship so she cannot hurt him. The plot then merges back at this point. This leads to the canon/true/good ending.
After leaving the wrecked ship, Ethan makes his way into an abandoned salt mine, where he finds a hidden laboratory. After some investigation, Ethan learns that Eveline is an „E-Series“ bioweapon, who can infect people with a psychotropic mold that allows her to brainwash and mind control them. Side effects of the infection include insanity, powerful regenerative abilities, and extreme mutations. She also grew up with an obsession of having a family of her own, which is why she infected Mia and the Bakers. Lucas is revealed to be working in secret with the unknown organization, as he has been given a serum that prevents him from being under Eveline’s control, and pretending to be under Eveline’s control so that he can keep his cover.
Using the lab equipment and the vial Mia gave him, Ethan is able to synthesize a toxin capable of killing Eveline and proceeds through the tunnels, eventually finding his way back to the original farmhouse. Upon learning that Ethan has the toxin, Eveline begins to assault him with powerful visions and hallucinations in an effort keep him away. Ethan is able to overcome her defenses and injects Eveline with the toxin, and is surprised to discover that Eveline was the unnamed elderly woman the entire time. However, the toxin causes Eveline to mutate further into a massive monster which attacks Ethan, who is only able to destroy her thanks to a special weapon dropped by a military helicopter.
With the threat over, Ethan is rescued by the Umbrella Corps Alpha team led by Redfield. If Ethan chose the Zoe path, then he will only find Mia’s personal effects in the helicopter, which he tosses out in grief over her loss. If Ethan chose the Mia path, then Mia is also rescued by Redfield’s team. Regardless of path, as the helicopter flies away, it bears the logo of the Umbrella Corps, a mercenary group which recovers samples of value to the bioweapons black market.