Outside Paris, a woman dumps a corpse in the river. The body is identified by Dr. Génessier as his daughter Christiane, who was reported missing after an automobile crash disfigured her face. In reality, Christiane still lives in Dr. Génessier's mansion next to his private clinic, guarded by German Shepherds and other large dogs. The body (which was disposed of by his assistant Louise) belongs to a young woman whose facial skin Dr. Génessier removed and unsuccessfully attempted to graft onto his daughter. After her father leaves with promises to restore her face, Christiane, wearing a mask to cover her disfigurement, calls her fiancé, Jacques Vernon, Dr. Génessier's assistant, but hangs up without saying a word. Génessier's next victim is Edna Grüber, a young woman whom Louise befriends and lures to Génessier's mansion with an offer of a room for rent. Génessier sedates Edna with chloroform, and he and Louise carry her to the lab to prepare her for surgery, secretly watched by Christiane. Later, he removes Edna's facial skin and grafts it onto Christiane's face. The heavily bandaged and faceless Edna attempts to escape but falls to her death from an upstairs window. After disposing of Edna's corpse, Génessier notices the new tissue is rejected within days, and Christiane has to wear the mask again. She phones Jacques and says his name, but Louise interrupts the call. Jacques informs the police, who have been investigating the disappearance of young women with similar facial characteristics. Jacques realizes one of the girls looks like Louise. Inspector Parot instructs Paulette Mérodon (recently arrested for shoplifting) to check herself into Génessier's clinic. Soon after, Paulette is picked up by Louise and delivered to Dr. Génessier. Before he begins surgery on Paulette, the police arrive. While the doctor talks with the police, Christiane, disenchanted with her father's immoral experiments, while slowly losing her mind from guilt and isolation, decides to act. She frees Paulette and murders Louise by stabbing her in the neck. She also frees the dogs and doves that her father uses for experiments. Dr. Génessier dismisses the police (who readily accept his explanations) and returns to his lab. There, a newly acquired German Shepherd attacks him, inciting the other dogs to follow suit, mauling him to death. Christiane, unmoved by his death, strolls out into the woods outside with a dove in her hands.

Calvin loves Chicago, his hometown and the place where he has been running his barbershop business in addition to supporting his family. Unfortunately, the city has become plagued by gang violence and criminal activity as of late, and tensions have begun to rise, especially in his neighborhood. Eddie comes running into the barbershop frightened because he claims to have made a comment at some thugs over their pants sagging. He gets Calvin panicked as the door starts banging, but it is really just a delivery man bringing him his breakfast, to his annoyance. Calvin and Angie now run the barbershop. It has a separate section for women to work, with new recruits Bree and Draya. On the men's side are Jerrod, Raja, and Rashad, new husband of Terri. Isaac and Jimmy no longer work there, but still keep in touch as customers. JD, the estranged cousin of former barber Ricky, has given up a life of crime and now runs a food truck business. However, he openly lies about what he does with the proceeds from the food truck business, claiming that he donates the money to charity. In truth, he and his overbearing grandmother keep the money for themselves. The shop also has a boy named Anthony Clark working there while he puts his focus on school. Rashad's son Kenny has been hanging out with Calvin's son Jalen. The boys come in one morning before school, and Calvin catches him trying to swipe two Snickers bars. Outside members of the Gangster Disciples pull up and try to steal the boys' sneakers, until the Vice Lords from the area appear and tell the other gang to step off. The Vice Lords leader, Yummy is friendly with the boys, assuming that they are willing to join his gang, and hands each boy a $100 bill. The men and women of the barbershop converse on the subject of modern women, with Bree arguing that good women are always losing to the "hoes," and that men complain about women having fake body parts but still lust after those same women. Another topic of discussion is racism against black people, which Raja disagrees with on the basis that the country has a black President, to which Rashad counters that Obama, a former Chicago resident, has done nothing when news involving murdered black children have been all over the media. Still, he insists that there has never been a better time to be a black person. Calvin has recently been talking to a smooth talking businessman called One-Stop about taking the barbershop business from the south side to the north side to avoid the dangers in the streets. Only his wife Jennifer is aware of this, and she's only considering for Jalen's sake. A regular client, Jay, enters for an appointment with Draya, but another man, Marquis, shows up, clearly having a beef with Jay. The two men nearly fight in the shop as it is revealed they are both "shot callers" from rival gangs, until he and Rashad intervene. The boys get in trouble at school after being involved in a fight with the gang from earlier that morning. Jalen is unharmed, but Kenny has a bruise under his eye. It pushes Calvin to consider putting his son in Catholic school, and also makes him trust Kenny even less, to the point where he confronts Rashad and tells him that they shouldn't be hanging out so much. Things get more serious when Jennifer goes through her son's dresser drawers and finds gang paraphernalia. With trouble going on in the neighborhood, Jimmy stops by and says there is a plan for an enclosure with heavy police presence, which would hurt the businesses. The members of the shop band together to organize a forum that night with the community to set up a ceasefire, along with free haircuts to anyone that passes by. Outside the shop, Terri becomes suspicious of Draya for being flirty and close to Rashad. He offers to take her home one evening on his way to pick up his daughter. She invites Rashad up to her apartment to talk, but Rashad knows what's up, even if she denies it being sexual, and declines her offer. The barbershop team set up for Jay and Marquis to arrive at the same time so they can get involved in the ceasefire. After a bit of tension and another near altercation, both men agree to the ceasefire out of respect for Calvin. Over the weekend, the ceasefire begins. Jerrod and Raja put the word out on Twitter for people to come to the barbershop. A large number of people show up, and things appear to be going smoothly. While at the barbershop, Rashad goes in the supply room in the back of the shop to grab some items, and Draya does as well. He apologizes for misinterpreting her motives from the other night. She forgives him but then tries to kiss him. Terri enters and heads into the back, looking for him. She catches the both of them hiding in the supply closet after he ignored her calling his name, leading her to believe they were hooking up. Terri attempts to fight Draya, chasing her to the front of the shop, however Calvin and the others stop her. She storms out and Rashad follows to try and explain himself, but she doesn't believe or trust him. As the shop celebrates a day of peace, Officer Terrence stops by to announce the tragic news that Anthony was shot to death on his way home from the library. Understandably devastated, Calvin gives up on the ceasefire and loses hope that they can make a difference in the neighborhood. The tension leads to Rashad revealing Calvin's intentions to move the shop to the north side of the city (after overhearing his conversation on a phone call) which infuriates Angie, since he kept his plans from her. Calvin storms out of the shop and goes to the bar, with Eddie joining him. He tries to assure Calvin that although Anthony's death was a tragic loss, they still may have prevented even more gunshot deaths. That inspires Calvin to return to his shop and apologize, while also restarting the ceasefire. Almost immediately, the shop gets a visit from Anthony Davis, which brings more attention to the shop. By evening the shop has even more business including media coverage, as well as becoming a trending topic on Twitter. JD brings his food truck and racks up some nice business as well, until his lies catch up to him and is guilt tripped into giving up a substantial amount of his earnings to a real charity. Terri returns to the shop and sees Rashad. She apologizes for accusing him of adultery and they reconcile. Kenny runs into the shop and tells Calvin that Jalen is at the park ready for a gang initiation, from which he had previously backed out. Calvin rushes to the park and his son is seen approaching Yummy about the initiation. When he gets there, the gang has left, but he stayed behind. Without a word, he joins his father. In the morning, the ceasefire comes to an end and the shop celebrates. Everyone begins to go home. Bree and Jerrod walk together, and they admit they have feelings for each other. They set up a dinner date for the next night. Draya later visits Terri and apologizes for coming onto Rashad, saying that she feels that Terri has her life figured out while she doesn't. Terri forgives her and Draya offers a proposition for the couple. Jalen visits his dad at the shop asking him to cut his hair. Calvin obliges and cuts off his dreads. They reaffirm they love each other and Calvin tells him to sweep the floor. Calvin says that he still loves his city, and he never gave up on it, since it had never given up on him. Father and son join Jennifer, Rashad, Terri and the kids. During the closing credits, the shop gets an unexpected visit from President Obama. Eddie volunteers to give the man a haircut after earlier claiming to have cut his hair years ago. Visibly nervous, Eddie messes up and accidentally shaves a good part on the back of the President's head.

A man named Swaaz, short for Schwarzenegger, robs a bank and gets chased by police. He orders his child assistant, Buddy Spencer, to jump from the car with the money as he leads police elsewhere. After being chased for some time, Swaaz is eventually trapped and is killed when he accidentally shoots his car, causing it to explode. In the slums of Kampala, Uganda, a young girl runs away from home and ends up in a child trafficking ring led by a former Uganda People's Defence Force commando in the ghetto. One day, while collecting metal scraps, she is viciously assaulted by multi-millionaire Hirigi when she mistakenly takes the tire iron from his van. After enduring weeks of abuse and witnessing the death of a friend, the girl takes matters into her own hands and kills the ringleader. Ten years later, the girl has grown up to become "Bad Black", leading the same group of ghetto children to become the biggest crime syndicate in Kampala. She seduces Hirigi in a bar to exact her revenge on him. Meanwhile, Alan Ssali, an American doctor whose whole family were allegedly U.S. Army commandos, is in Kampala giving aid to the people of the slums. He encounters Bad Black, who mistakes him for a commando due to his designer dog tags. After receiving Alan's business card, Bad Black sneaks into his hotel and steals his money and passport. When the police refuse to help him, Alan receives " kung fu commando training" from his young assistant, known by his pseudonym " Wesley Snipes ", before storming through the slums to look for Bad Black. Hirigi's teenage son, Kenny, is banished by his father and goes to Black's gang in search for drugs. Hirigi tells Black about his plans to buy the ghetto and throw the gang out. Bad Black brings Hirigi to her grandmother, where it is revealed that Hirigi is her grandfather and that he has been dating a ghetto woman. Hirigi threatens Bad Black by throwing her out and runs away disgusted. One day, a drug deal between Bad Black and a rival syndicate is disrupted by police. The gangsters frantically run away only to be gunned down by Alan, who corners Bad Black and recovers his dog tags and hands her to the police. At the prison, she's intimidated by the prison gang leader Supazilla, but eventually befriends her. Bad Black then meets a fellow female inmate named Flavia who claims that her rich father banished her and that she never got to see her own child after birth before being taken to prison. Later that night, Kenny and the syndicate attempt to break Bad Black out. The following riot allows two other women to escape, but Bad Black stays with Flavia to comfort her as she is set to be released in two days; Bad Black is caught offscreen, and Kenny is subdued and captured alive. Days later, Flavia is released and is present at Bad Black's trial. Bad Black explains that her father was Swaaz and that he robbed the bank to pay for the expenses of her birth but also claims that her mother was killed during the birth. It is then revealed that Flavia is Bad Black's mother and the two hug as the court is adjourned. Three months later, Alan resumes his medical mission in Wakaliga, but with Bad Black as his nurse. Hirigi's wife suddenly appears and opens fire at the medical camp, killing Alan in the process.

Henry Spencer's face appears superimposed over a planet in space. He opens his mouth and a spermatozoon -like creature emerges. A man inside the planet moves a set of levers, and the creature is flushed away. In an industrial cityscape, Henry walks home with his groceries. He is stopped outside his apartment by a woman across the hall, who informs him that his girlfriend, Mary, has invited him to dinner with her family. Henry leaves his groceries in his apartment, which is filled with piles of dirt and dead plants. That night, Henry visits Mary's home, conversing awkwardly with her mother. At the dinner table, he is asked to carve a Cornish game hen; the bird moves and writhes on the plate and gushes blood when cut. After dinner, Henry is cornered by Mary's mother, who tries to kiss him. She tells him that Mary has had his child and that the two must wed. This causes Henry to have a nose bleed. However, Mary is not sure if what she bore is a child. The couple moves into Henry's one-room apartment and begins caring for the child, a swaddled bundle with an inhuman face that resembles the spermatozoon creature seen earlier. The infant refuses all food and cries incessantly and intolerably. The sound drives Mary hysterical, and she leaves Henry and the child. Henry attempts to care for the child, and he learns that it struggles to breathe and has developed painful sores on its skin. Henry begins experiencing visions, again seeing the man in the planet, as well as a lady who inhabits his radiator and stomps more of the sperm creatures. After a sexual encounter with the girl across the hall, he has another vision in which the lady in the radiator sings (" In Heaven "), and his head pops off his body while he is fidgeting, replaced by the baby's crying head. Henry's disembodied head falls from the sky, landing on a street and breaking open. A boy finds it and takes it to a pencil factory to be turned into erasers. Awakened, Henry seeks out the girl across the hall, but finds her with another man. Crushed, Henry returns to his room. He takes a pair of scissors and for the first time removes the child's swaddling clothes. It is revealed that the child has no skin; the bandages held its internal organs together, which proceed to spill out after the bandages are cut. The child gasps in pain, and Henry stabs its organs with the scissors. The wounds gush a thick liquid, covering the child. The power in the room overloads, causing the lights to flicker; as they flick on and off the child grows to huge proportions. As the lights burn out completely, the child's head is replaced by the planet seen at the beginning. Henry appears amidst a billowing cloud of eraser shavings. The side of the planet bursts apart and the man inside struggles with his levers, which emit sparks. Henry is embraced warmly by the lady in the radiator in a white void.

When a landfill is overfull, and pollution reaches its maximum, a monster is born. Made from garbage and bearing a resemblance to a giant humanoid fly in a gas mask, the Milpitas Monster has an uncontrollable desire to consume large quantities of garbage cans. Some high school students find out about the monster and attempt to destroy it.

In September 1942, U.S. Army Corps of Engineers Colonel Leslie Groves, who oversaw the construction of the Pentagon, is assigned to head the ultra-secret Manhattan Project, to beat the Germans, who have a similar nuclear weapons program. Groves picks University of California, Berkeley, physicist J. Robert Oppenheimer to head the project team. Oppenheimer was familiar with northern New Mexico from his boyhood days when his family owned a cabin in the area. For the new research facility, he selects a remote location on top of a mesa adjacent to a valley called Los Alamos Canyon, northwest of Santa Fe. The different personalities of the military man Groves and the scientist Oppenheimer often clash in keeping the project on track. Oppenheimer in turn clashes with the other scientists, who debate whether their personal consciences should enter into the project or whether they should remain purely researchers, with personal feelings set aside. Nurse Kathleen Robinson and young physicist Michael Merriman question what they are doing. As Michael works with no protection from radiation during an experiment dubbed Tickling the Dragon's Tail, a probe he is holding slips from an apparatus and he is instantly bathed in a blue light, which is a visible result of a lethal dose of radiation. In the base hospital, nurse Kathleen can only watch as he develops massive swelling and deformation before dying a miserable death days later. While the technical problems are being solved, investigations are undertaken to thwart foreign espionage, especially from communist sympathizers who might be associated with socialist organizations. The snooping reveals that Oppenheimer has had a young mistress, Jean Tatlock, and he is ordered by Groves to stop seeing her. After he breaks off their relationship without being able to reveal the reasons why, she is unable to cope with the heartache and is later found dead, apparently a suicide. As the project continues in multiple sites across America, technical problems and delays cause tensions and strife. To avoid a single point of failure plan, two separate bomb designs are implemented: a large, heavy plutonium bomb imploded using shaped charges (" Fat Man "), and an alternative design for a thin, less heavy uranium bomb triggered in a shotgun or gun-type design (" Little Boy "). The bomb development culminates in a detonation in south-central New Mexico at the Trinity Site in the Alamogordo Desert (05:29:45 on July 16, 1945), where everyone watches in awe the first mushroom cloud with roaring winds, even miles away. Both bombs, Fat Man and Little Boy, are successful, ushering in the Atomic Age.