THE LAZARUS EFFECT
NOTE: This spoiler was submitted by Jeremy.
We see video footage of a dead pig lying on an operating table. A team of medical researchers are performing an experiment to bring it back to life. They inject it with a serum and hit the switch to their machine, but nothing happens. One researcher jokes about eating the pig, and then the pig starts to squeal briefly before staying dead.
The team works at a university in Berkeley, California. One of the scientists, Zoe McConnell (Olivia Wilde), guides a student, Eva (Sarah Bolger), to the lab so that she can record the team's experiments and research. Zoe introduces Eva to her co-workers Niko (Donald Glover), Clay (Evan Peters), and Zoe's fiance and the head of the project, Frank Walton (Mark Duplass). While Clay ogles Eva, it's clear that Niko has feelings for Zoe. Frank explains that their serum, codenamed "Lazarus", began as a means to retain neural activity in coma patients, and is now used for the means of bringing the dead back to life. They test the serum on a blind dead dog named Rocky. At first, it appears that nothing happened, but Rocky begins to bark and move around. The team celebrates with a bottle of champagne.
Frank and Zoe take Rocky home with them. The dog's cataracts disappear and it experiences a loss of appetite. It also displays slightly aggressive behavior. The team discovers that the serum is still in Rocky's brain, despite the fact that it should have dissipated within hours.
At night, Zoe has a nightmare of being in a burning apartment building. There are burnt hands sticking out from underneath a door. Zoe awakens with a gasp. Frank comes in to comfort her.
Clay is left alone in the lab with Rocky while he sits in his cage. He turns away from the dog for a brief moment, and he hears a crash. Clay goes to find the fridge opened and food spread out everywhere. He then sees Rocky growling viciously at him. When the team comes back, Clay mentions what he saw, but nobody seems to believe him.
The dean of the university calls Frank in to chastise him for the underground experiments, unhappy that he and the team are trying to play God. Frank learns that someone has been giving the dean footage of the experiments that show them testing the serum on animals. The shareholders later show up at the lab and confiscate every bit of equipment and research that the team has after they are told that a major pharmaceutical corporation bought out the company that was funding the project. Zoe accuses Eva of being the one that told the dean, since this happened after she showed up.
Using a security pass that Eva kept, the team sneaks back into the lab at night to recreate the experiment. Niko hacks into the security system to buy them time. The team gets another dead dog and gets it prepped for another test. Zoe flips the switch, and she is electrocuted. Frank rushes to her side and feels that she has no pulse. Niko hands him an adrenaline needle that he sticks in Zoe's chest, but she remains unresponsive. Clay brings over the defibrillators, which also doesn't work. Zoe is dead. Frank then sees that she had her engagement ring on her finger, which caused the electrocution.
Not ready to let her go, Frank puts Zoe's body on the table. Clay, Niko, and Eva all argue that this is wrong since they know Frank is gonna try the serum out on a human being. Accepting whatever consequences are in store for him, Frank goes ahead with the test. He injects Zoe with the serum. She is still unresponsive. Niko then sees that the security guard is headed their way. They hide from him until he leaves, at which point the team sees Zoe sitting up on the table. Frank goes over to her and checks for anything unusual. Zoe grabs his wrist and asks if she just died. She then appears to be able to hear everyone's thoughts.
At home, Zoe notices her fingertips look darkened, as well as the spot where Frank injected her. She tells him that she feels there is something wrong with her. She says that she felt herself in the burning apartment building, but she couldn't get herself out. Frank dismisses it as just a bad dream, like the ones she always has. After he leaves, Zoe moves a pen with her mind.
The team returns to the lab with Zoe. She is left alone with Eva while the guys step out. Eva leaves Zoe to sleep. She walks out and finds herself in the same burning building. Eva sees a little girl standing in the hallway holding something in her hand. The little girl runs away, and Eva sees the burning hands reaching out. A burning hand then grabs her wrist, and she wakes up screaming as the guys find her. She tells them what she saw, and that she also has a visible burn on her wrist. Frank explains that Zoe had a traumatic childhood experience in which she was trapped in the burning building and that she saw her neighbors sticking their fingers out, unable to escape. Eva suggests that Zoe saw something when she died, and that maybe her soul is trapped.
Niko is alone in the room on his computer when he's startled by Zoe. She begs him to help her figure out what's wrong with her, attempting to manipulate him with a kiss. He rejects it, knowing it's wrong. The lights go out, and Zoe disappears. Through a security camera, it's seen that Niko is pulled into a closet. Zoe reemerges and telekinetically crushes the closet with Niko inside, killing him.
Frank, Eva, and Clay return, demanding to know where Niko is. Zoe appears calm and doesn't tell them anything. Clay tries to call for help, but the power goes out, taking out the emergency lines as well. He yells at Zoe for her to tell them where Niko is, and she uses her powers to choke Clay with his e-cigarette. Frank and Eva try to save him, but it's too late. They are horrified when they pull the e-cig out of his mouth. Zoe disappears again.
Now realizing that something is very wrong, Frank and Eva attempt to catch Zoe with a syringe to incapacitate her. Frank finds Zoe in the hall, sobbing. He goes to her and says the Zoe he loves is still in there. She reads his mind and hears that he doesn't think she's the same Zoe. She grabs his head and squeezes it until his neck snaps. Eva flees after seeing this. Zoe then grabs the rest of the serum and injects herself with all of it.
The lights continue to go out, leaving Eva in the dark with Zoe. Eva appears to get thrown into the burning building again. She encounters the little girl, whom Eva realizes is Zoe. Little Zoe hands Eva a book of matches, revealing that it was she that started the fire. Eva tells her that it wasn't her fault and that she can fix this. Evil Zoe then comes in with her skin burning and her eyes blackened. Little Zoe goes to open the neighbors' door as Evil Zoe comes closer. Little Zoe opens the door, and a blinding white light flashes before their eyes...
Eva sticks Zoe with the syringe. Zoe apologizes for what she's done, and she collapses. Eva slumps over as sirens are heard. A fireman runs in with a response team. He goes to Eva and comforts her. Eva then sees that Zoe's body is gone. She looks at the fireman, which is really Zoe. She then breaks Eva's neck.
Zoe lines up the bodies of Clay, Niko, and Eva next to each other. She puts Frank's body on the table and injects him with the serum from her body. Frank then comes back to life with a gasp.