Tim Lake grows up in Cornwall with his father James, mother Mary, uncle Desmond, and younger sister Katherine ("Kit Kat"). The morning after a less-than-great New Year’s Eve party, James tells Tim that the men of their family can travel back in time to moments they have lived before. Tim tests this by going back to the previous night’s party and changing a few events. When he returns, James discourages him from using his gift to acquire money or fame, due to the boredom felt by other family members. Tim decides to use it to improve his love life. The following summer, Kit Kat's friend Charlotte visits. Although instantly smitten, Tim waits until the last day to tell her; she tells him he should have told her earlier. Tim travels back in time to tell Charlotte in the middle of the holiday, but she suggests he wait until her last day. Heartbroken, he realises that she is uninterested in him and time travel cannot change anyone's mind. Tim moves to London to pursue a career as a lawyer, initially living with his father's acquaintance Harry, a playwright. He visits a Dans le Noir restaurant, where he meets Mary, an American who works for a publisher. They flirt in the darkness, and she gives Tim her phone number. He returns home to a distraught Harry, whose play's opening night has been ruined by an actor forgetting his lines. Tim goes back in time to help the actor so the play is a triumph. However, when Tim tries to call Mary, he discovers that by going back to help Harry, the evening with her never occurred so he does not have her number. Recalling Mary's obsession with Kate Moss, he attends a Kate Moss exhibition every day until he sees Mary. Having never met Tim, she is confused but allows him to join her and her friend. During lunch, he discovers that she now has a boyfriend. Tim goes back to when they met, turning up before the potential boyfriend arrives, and persuades Mary to leave with him. Their relationship develops, and Tim moves in with Mary. One night, he encounters Charlotte, who is now interested in him, but he turns down the invitation of intimacy as he is in love with Mary. Tim returns home and proposes. They marry, and shortly afterwards have a baby daughter, Posy. Kit Kat's toxic relationship and employment struggles lead her to drunkenly crash her car on Posy's first birthday. Tim decides to intervene: he prevents the crash and, breaking the tradition of keeping the time travel ability secret, takes her back to avert the bad relationship. Returning to the present, he finds that Posy has never been born but he has a son instead. James explains that changing events prior to their children's birth may alter the exact child conceived. Tim accepts that he cannot solve his sister's problems by changing her past; he lets the crash happen, ensuring Posy's birth, and he and Mary help Kit Kat face her problems. She settles down with Tim's friend Jay. Tim and Mary have another child, a boy. Tim learns that James has terminal lung cancer and time travel cannot change it, as going back to remove his smoking would undo his and Kit Kat's conceptions. His father has known his illness would come for some time, and so has been travelling back in time to extend his life and spend more time with his family. He tells Tim to live each day twice to be truly happy: first, with all the everyday tensions and worries, but the second time noticing how sweet the world can be. Tim follows this advice; his father dies, but on the day of the funeral, Tim travels to the past to visit his father. Mary tells Tim that she wants a third child. He is reluctant as he will not be able to visit his father again. Tim tells James, so together they travel back to relive a happy memory from Tim's childhood, taking care not to change the experience to avoid causing changes to the present. Mary gives birth to another girl. Jay and Kit Kat, very happy together, have their first child. The family accepts the loss of James, and Tim realises that it is better to live each day once only. He ultimately decides to not time travel at all and comes to appreciate life with his family as if he is living it for the second time.

Bernard Lawrence is an American journalist stationed in Paris. A playboy, he has devised an ingenious system for juggling three girlfriends: he dates flight attendants who are assigned to international routes on non-intersecting flight schedules so that only one is in the country at any given time. He has their routes detailed with such precision that he can drop off his British United Airways girlfriend for her outgoing flight and pick up his inbound Lufthansa girlfriend on the same trip to the airport, while his Air France girlfriend is in a holding pattern elsewhere. With help from his long-suffering housekeeper Bertha, who swaps the appropriate photos and food in and out of the apartment to match the incoming girlfriend, Lawrence keeps the women unaware of each other's presence in the apartment. They regard Lawrence's flat as their "home" during their Paris layovers. Bernard is so happy with his life in Paris that he intends to turn down an imminent promotion that would require him to move to New York City. But his life is turned upside down when his girlfriends' airlines begin putting new, state-of-the-art jet aircraft into service. These faster airplanes change all of the existing route schedules and allow flight attendants to spend more time in Paris. Most alarming for Bernard, his three girlfriends will now all be in Paris at the same time. Robert Reed, a fellow journalist and an old acquaintance, complicates Bernard's life even further when he arrives in town and is unable to find a hotel room. He insists on staying in Bernard's apartment for a few days. When he sees Bernard's living situation, he schemes to take over Bernard's apartment, girls, housekeeper and job while manipulating Bernard into taking the new job in New York.

Friends Felix and Leon are driving to Felix's family holiday home on the Baltic Sea not far from Ahrenshoop when their car breaks down. After walking through the forest with their luggage, they arrive at the house to find it unexpectedly inhabited by Nadja, whose presence is obvious though they do not meet her. Her romantic trysts keep them up at night, causing Leon to resent her. Over the course of their vacation forest fires are mentioned, first distantly, then approaching. Leon spends his time fussing over the manuscript of his second novel, while Felix is less hurried about completing his photography portfolio. Within a couple days, they have both met Nadja, who is kind and accommodating. Despite this, Leon continues to be frustrated by her. Meanwhile, Felix strikes up a friendship with her and her lover, Devid, a lifeguard at the nearby beach. The emotions among the four intensify as Leon broods and resists interacting with the others. Felix and Devid develop a romantic and sexual relationship. Nadja offers friendship to Leon but he struggles to accept it. After much consternation, he decides to grant her request to read his manuscript, which she finds inferior and she tells him that he knows its poor quality. Leon does not take this well and isolates himself for the rest of the evening. When Leon's publisher Helmut arrives so they can review the manuscript together, Leon grows even more despondent as Helmut connects more with Felix, Devid, and especially Nadja, who is revealed to be a doctoral candidate in literature, not the seasonal hotel employee Leon thought. After a dinner that is tense for Leon and enjoyable for the rest, the forest fires are close enough that ash begins to fall just as Devid and Felix finally leave to retrieve their abandoned car. Helmut suffers a medical emergency. Nadja is quick to act, driving Helmut's tiny rental car to the hospital. Leon follows on foot. On the way, he sees wild boar fleeing the fire. After he watches a boar die, the fire begins to crest the hill and he runs. In darkness, he reaches the hospital to join Nadja, asleep on a bench. When they wake in the morning and find Helmut, he shares private moments with both of them. Nadja asks about his health, which he has lied about so as not to trouble them, and informs him of Leon's distress. Helmut comforts Leon, advising him to abandon his work-in-progress but assuring him of eventual success. Helmut promises to help him as long as his condition allows. On the walk back to the house, Nadja offers Leon comfort which Leon angrily rejects, leading Nadja to castigate him for his self-centeredness before leaving him alone on the beach. Remorseful, he follows her back to the house where he begins to confess romantic feelings for her, just as she sees two police officers in the backyard. Nadja approaches them and they inform her that Devid and Felix were found burned to death by the fires. Nadja and Leon go to see their bodies and see their charred corpses intertwined in death. Nadja has a profound emotional reaction, but Leon cannot absorb the reality, instead thinking about other coupled corpses throughout history, such as those found at Pompeii. She leaves without him, and by the time he reaches the vacation house she has left. He goes to the beach and sobs, looking at the bioluminescence in the sea, something he had refused to do earlier. Some time later, Leon is in Helmut's hospital room as Helmut reads Leon's new manuscript back to him, a work of autofiction based on the time he shared with Felix, Nadja, and Devid. Together they look at photos Felix took that summer which Helmut wants to use as accompanying artwork for the novel. Helmut has Leon leave when a medic appears to administer a treatment. Waiting outside, Leon sees Nadja arriving, presumably to visit Helmut. He steps out from hiding and the two share a moment of mutual recognition.

During the Great Depression, Clyde Barrow and Bonnie Parker of Texas meet when Clyde tries to steal Bonnie's mother's car. Bored with her job as a waitress, Bonnie becomes intrigued by Clyde and decides to partner with him in crime. They pull off some holdups, but their amateur efforts, while exciting, are not very lucrative. Bonnie and Clyde turn from small-time heists to bank robbing. The duo's crime spree shifts into high gear once they hook up with a dim-witted gas station attendant, C.W. Moss. Their exploits also become more violent. After C.W. botches parking during a bank robbery and delays their escape, Clyde shoots the bank manager in the face when he jumps onto the slow-moving car's running board. Clyde's older brother, Buck, and his wife, Blanche, a preacher's daughter, also join them. The two women develop an immediate dislike for each other, which only intensifies over time. Blanche has nothing but disdain for Bonnie, Clyde, and C.W., while Bonnie sees Blanche's flightiness as a constant danger to the gang's survival. In Joplin, Missouri, local police show up at the gang's rented house after being alerted by a grocery delivery boy; two policemen are killed in a shootout. The gang is pursued by law enforcement, including Texas Ranger Frank Hamer, whom they capture and humiliate before leaving him adrift on a boat while handcuffed. The five outlaws then pull a heist, during which a police chase disables their vehicle. They steal Eugene Grizzard's car and take him and his girlfriend captive before quickly abandoning them when they learn he is an undertaker. Bonnie wants to visit her family in Texas and give them part of the heist funds, to which Clyde reluctantly acquiesces despite the risk. An ambush by law enforcement overnight catches the gang off guard, resulting in numerous casualties. Buck is mortally wounded by a shot to his head, and Blanche is injured in one eye, losing sight in it. Bonnie, Clyde, and C.W. barely escape alive, while Blanche falls into police custody. Hamer then tricks her into revealing C.W.'s name (until then he was only an "unidentified suspect"). C.W. takes the wounded Bonnie and Clyde to hide out at the house of his father, Ivan, who thinks the couple has corrupted his son (as evidenced by an ornate tattoo Bonnie convinced C.W. to get). The elder Moss makes a deal with Hamer: in exchange for mercy for C.W., he sets a trap for the outlaws. When Bonnie and Clyde stop on the side of the road to help Mr. Moss fix a flat tire, as a nearby flock of birds flies away, the posse in the bushes guns the couple down. Hamer and his men come out of hiding and gather around the couple's bodies.

In 1978, Baton Rouge pilot Barry Seal, who flies commercial jets for TWA, is recruited by CIA case officer Monty Schafer. He asks Seal, who has been smuggling Cuban cigars into the country to make a little money, to fly reconnaissance missions over Central America using an Aerostar 600, outfitted with aerial surveillance cameras. Seal accepts the job, but hides it from his wife, Lucy. In the 1980s, Schafer asks Seal to act as a courier between the CIA and General Noriega in Panama. During a mission, the Medellín Cartel picks Seal up and asks him to fly cocaine on his return flights to the US. Seal accepts and flies the cartel's cocaine to Louisiana, airdropping the drug in the countryside. The CIA turns a blind eye to the drug smuggling, but the DEA tracks Seal down. To avoid the authorities, Seal and his family relocate to Mena, Arkansas and his wife comes to accept the wealth generated by his side job. The small town becomes wealthy as the hub of US cocaine trafficking. Later, Schafer asks Seal to run guns to the Nicaraguan Contras in Honduras. Realizing the Contras are not serious about the war and just want to get rich, Seal starts trading the guns to the cartel. The CIA sets up a Contra training base in Mena and Seal flies the Contras in, but many of them escape as soon as they arrive. Seal makes so much money he buries it in suitcases in the backyard. Seal's freeloading, unemployed brother-in-law JB moves in. JB starts stealing money and is arrested with a briefcase full of cash. With JB out on bail, Seal gives him money and a plane ticket to Bora Bora for his safety. JB demands weekly cash and insults Lucy. As Seal chases after him, JB is killed by a car bomb placed by the Medellín Cartel, who had previously promised to "take care" of the JB problem. The FBI catches wind of the sudden exuberance on the streets of Mena, not helped by JB's reckless spending. Eventually, the CIA shuts down the program and abandons Seal, who is arrested by the FBI, DEA, ATF and Arkansas State Police simultaneously. Seal escapes prosecution by making a deal with the White House, which wants evidence of the Sandinistas being drug traffickers. They ask him to get photos that tie the Medellín Cartel to the Nicaraguan Sandinistas. Seal manages to get them, but the White House releases them as propaganda against the Sandinistas. Seal is prominently shown in the pictures, which leads to his indictment by the crusading state attorney general and the cartel plotting revenge. Seal is convicted but sentenced to only 1,000 hours of community service. Moving from motel to motel making video recordings detailing his experiences, Seal expects an explosion any time he starts his car. As his community service is performed at the same Salvation Army building every night, Seal cannot hide from the cartel and is shot dead by an assassin. The CIA destroys all evidence connecting them to Seal and continues smuggling, instead using Iran to get guns to the Contras, as proposed by Schafer. The film ends with Schafer getting promoted for his idea, though it is soon discovered by the public with reporters asking President Reagan and Vice President Bush about the scandal. Lucy and her kids move back to Baton Rouge, where she is seen contentedly working in fast food. One of her expensive pieces of jewelry is seen on her wrist.