context: This film is loosely based on H. G. Wells' "The Invisible Man", with Dr. Sebastian Caine (actor Kevin Bacon) taking the place of Doctor Jack Griffin (actor Claude Rains) and updates the story to the 20th Century. In this version of Wells' story, the doctor is a brilliant, but megalomaniacal, molecular biologist, and is working on an invisibility serum for the U.S. military, as well as a serum that will return the subject back to visibility. Sebastian has been attempting to perfect the formula for the last four years, and he conducts his experiments on animals kept inside a top-secret hidden military lab accessible only to him and his staff. His current project is reversing the invisibility effect on his test subject, a female gorilla named Isabelle. Working late one night on re-configuring the molecular model of the irradiated protein that will restore Isabelle to visibility, he solves the problem and immediately reports his success to the top members of his staff.Although work on the serum occupies nearly all of his waking hours, Sebastian becomes obsessed with his ex-girlfriend Dr. Linda McKay (Elisabeth Shue), who is a scientist on his team. Unbeknownst to him, she has become involved with Dr. Matt Kensington (Josh Brolin), another member of their research group. Sebastian and his colleagues, who also include veterinarians Sarah Kennedy (Kim Dickens) and Carter Abbey (Greg Grunberg), and technicians Frank Chase (Joey Slotnick) and Janice Walton (Mary Randle), eventually enable the serum to work on the gorilla. In celebration, the team goes out for a fancy dinner, where Sebastian makes a toast to the greatest research group in the world. To Sebastian, however, it feels like the end as reversion was the last big breakthrough.Instead of reporting his success to the military, Sebastian inexplicably lies to the oversight committee including his old teacher Dr. Howard Kramer (William Devane), and talks Linda and Matt into lying to the other four and going right into human testing. The subject: Sebastian, himself. Despite a painful shift to transparency, the procedure is successful. After being unconscious for about 17 hours due to shock, Sebastian wakes up in pain, and recoiling from the ambient light, realizing that he can see through his eyelids. He then conducts some clinical tests on himself. But when it comes time to return to visibility after three days, the reversion fails and almost kills him.The researchers construct a latex mask for the scientist to wear around the lab, crudely approximating a human appearance. During this time, Matt discovers a promising way to make Sebastian visible again. A computer simulation, however, fails. Over the next several days, isolation and virtual imprisonment in the lab begin to wear on Sebastian's patience. Disobeying Carter and his own rules, he heads back to his apartment to grabs some books, CDs and Twinkies to take back to the lab. There, temptation gets the best of him, and he first spies on his neighbor (Rhona Mitra), and then rapes her, while fully invisible. Linda shows up at the apartment and finds the mask and clothes, but no Sebastian.Sebastian returns to the lab just as the others were planning to go after him. Linda warns him that if he leaves again, she and Matt will tell Dr. Kramer what they did. Ignoring their threat, he assembles a device that runs a video loop of his heat signature in his quarters; the repeating image fools Frank into believing that Sebastian is still in the lab, when, in fact, he is out spying on Linda and Matt.Sebastian is furious that Matt and Linda are together, and smashes their bedroom window. The two call Frank, who tells them that Sebastian is still in bed. Meanwhile, an enraged Sebastian returns to the lab, frustrated and angered at the thought of Linda and Matt together. Unable to stand the annoying barking of an invisible dog, Sebastian approaches the dog, reassuring it that he means it no harm, then kills it with his bare hands by brutally smashing it against the cage wall. The team soon discover that they have been watching a recording and that Sebastian has been leaving without their knowledge.Linda and Matt go to Dr. Kramer's house and confess about their experiments with Sebastian. Dr. Kramer is disappointed, and tells them that they are fired from the project. Dr. Kramer then attempts to call the military and inform them about Sebastian, but Sebastian has actually followed Linda and Matt to the house. Sebastian tricks Kramer into leaving the house and then drowns him in his own swimming pool.The next day, Sebastian waits until all of the team is in the lab and then disables the phones and all of the elevator codes except for his own. He removes his clothing and latex mask and, invisible, begins to hunt them all down. Janice falls behind while the team searches for Sebastian and he strangles her with an IV line and stuffs her body in a locker.Linda, Matt, Sarah, Carter, and Frank learn what Sebastian is up to, realizing that they are the only ones who know what he has become, and therefore he is planning to kill them all. Linda, Sarah, and Frank hide in the lab while Matt and Carter take tranquilizer guns to go hunting for Sebastian in the empty hallways using thermographic imaging goggles. Matt shoots at a heat signature that turns out to be from a steam vent. When Matt turns around, Carter has been yanked into the air by Sebastian, who is on top of a pipe. Matt tries to shoot him, but Sebastian throws Carter down toward a steel bar, which cuts his carotid artery, causing massive blood loss. Sebastian almost kills Matt, but Linda drags him to safety.Sarah and Frank find the barely conscious and severely injured Carter. Sarah runs to the freezer to get blood for a transfusion, despite Frank's wishes. There, Sebastian corners her. She splashes the blood all over the room, rendering him visible, however, Sebastian tackles her and shoots her with her tranquilizer dart, then breaks her neck.Linda and Matt find Frank tending to a dying Carter. Carter bleeds to death and the three go to find Sarah. They find her dead in the walk-in freezer. Frank sprays a fire extinguisher to expose Sebastian, but Sebastian comes from behind impales Frank with a crowbar. He then stabs Matt with the hook end, however non-fatally. Sebastian locks Linda and Matt in the freezer, turns the temperature control all the way down and leaves them to freeze to death.Sebastian puts on his latex mask and clothing, spending much time to ensure he looks near-human. Meanwhile, Linda dresses Matt's wound with duct tape and then works out a way to escape from the freezer. Linda constructs an electromagnet using a defibrillator and other lab equipment, and uses it to open the door. She lights a fire to warm Matt and gathers the parts needed for a flamethrower. Sebastian goes to the lab and produces nitroglycerin to blow up the lab. He puts the nitro in a centrifuge, starts a timer and destroys the keyboard, so it can't be stopped. Just as he is entering the elevator to leave, Linda appears and fires her crude blowtorch at him. His latex mask and clothes burning away, Sebastian barely manages to escape the flames. Linda uses the flamethrower to start the ceiling sprinklers, partially revealing him. The two fight; just as she is about to lose, Matt appears and hits Sebastian with the crowbar. Sebastian recovers, but while wet, he swings the crowbar and connects with a fuse box, electrocuting himself. As the electricity courses through his body, Sebastian is rendered partially visible: his muscles, bones, and organs can be seen, but his skin and what's left of his hair remain invisible.Linda and Matt find the nitro about to explode, and decide to abandon the lab, climbing up the elevator shaft. The lab explodes filling the shaft with fire. The two are almost out when Sebastian appears. He fights with Linda, and kisses her one last time "for old time's sake" before she finally kills him by grabbing the elevator cable and knocking the car loose, sending Sebastian plummeting into the inferno below. Eventually, both Linda and Matt emerge from the burning laboratory, and medics whisk them away in an ambulance.
question: Who is the serum tested on ?
answer: Sebastian.