Lightning

On a stormy night in January 1955, a mysterious blond stranger intercepts Dr. Paul Markwell, a physician with an alcohol addiction, at gunpoint and prevents him from delivering a baby at a Denver hospital. The stranger calls to report Markwell's condition, ensuring a competent doctor handles the delivery instead. Laura Shane's mother, Janet, dies from complications, but the baby girl survives. Bob Shane, Laura's father and a humble grocer, finds hope in his newborn daughter. The next morning, the stranger watches Laura through the nursery window and tells Bob she is beautiful. A sinister adversary of the guardian named Kokoschka, a cold man with a dueling scar, also watches the infant, considers killing her, but decides to wait.

Eight years later, a junkie robs Bob's grocery store in Santa Ana and threatens to sexually assault Laura. The blond stranger enters through the back, shoots the junkie dead, and coaches Bob and Laura to tell police a cover story. He identifies himself only as Laura's "guardian angel." In intercut scenes, the guardian plants explosives in a heavily secured institute in a war-darkened city. A barrel-shaped device called "the gate," a breach in time, dominates the main laboratory. The guardian plans to destroy the institute and its files.

When Laura is twelve, her father dies of a heart attack. At the cemetery, she spots her guardian and chases him. Kokoschka approaches and asks, "Why you?" but retreats when Cora Lance, a family friend, draws near. Laura later finds an unsigned note from her "special guardian," promising happiness will come.

Laura enters the child-welfare system at McIlroy Home, where she befriends twin sisters Ruth and Thelma Ackerson. Willy Sheener, a pedophilic custodian, fixates on Laura; her guardian beats him severely. After a neglectful foster placement, Laura is placed with Carl and Nina Dockweiler, a loving couple in Newport Beach. Nina has a congenital heart defect. Sheener breaks into the home and attacks Laura; she kills him with a broken glass tumbler. Nina arrives, sees the carnage, and dies of a heart attack. Laura returns to McIlroy, devastated and losing faith in her guardian. A troubled fellow resident named Tammy Hinsen later sets herself on fire. Ruth dies trying to smother the flames, and Thelma escapes, consumed by guilt. Laura and Thelma later share a room at Caswell Hall, bonded by shared loss.

Meanwhile, Kokoschka tracks the guardian's unauthorized trips through time, discovers his interest in Laura is personal, and decides to kill her in front of him before executing him.

In adulthood, Laura traces anonymous ceramic toad figurines, echoing a childhood fantasy her father created, to Daniel Packard, a shy stockbroker who fell in love with her writing. They marry, and Laura's career accelerates: Her second novel, Shadrach, sells at auction for over a million dollars. She gives birth to Christopher Robert Packard but hemorrhages severely and can never have more children. Thelma's comedy career ascends through nightclub and television appearances.

On January 10, 1988, the guardian flags the family down on an icy highway, saving them from a sliding pickup truck. Moments later, Kokoschka arrives and opens fire with a submachine gun. Danny charges the gunman and is killed. The guardian shoots Kokoschka dead, strips a strange belt from the body, and gives it to Laura. The belt is a time-travel device linked to the gate. He warns Laura to arm herself, activates his own belt, and vanishes, leaving her with no explanation.

Laura spends the following year fortifying herself and Chris with firearms training, martial arts, hidden weapons, and a home tutor. On the first anniversary of Danny's death, Stefan Krieger, her guardian, collapses on her patio with a bullet wound, warning that assassins are coming. She loads him into the Jeep. Moments later, men in black attack the house with submachine guns. Laura kills two of them, escapes in the Jeep, and outruns the pursuers before reversing course when Chris reasons that the assassins might set a time-travel ambush ahead. She forces a physician to treat Stefan's wound, fights off more assassins, and hides at a motel after swapping vehicles.

When Stefan regains consciousness, he reveals his origins. He comes from Nazi Germany in 1944. There, scientist Vladimir Penlovski, under Hitler's patronage, built the time-travel gate at a secret Berlin institute. The gate allows travel only forward in time; homing belts return travelers to 1944, 11 minutes after departure. Nazi teams traveled to 1985 to gather nuclear-weapons data. Stefan planted explosives and killed key scientists, but a power failure stopped his detonator, and Kokoschka, the institute's security chief for the Gestapo (the Nazi secret police), shot him as he escaped through the gate.

Stefan explains that on an earlier trip, he saw Laura at a 1984 book signing, using a wheelchair because the drunken Markwell had botched her delivery. He fell in love with her courage and writing, then traveled back to 1955 to ensure she was born whole. Every intervention aimed to improve the life fate ordained for her. He could not save Danny because that event was part of his own immutable past.

Laura contacts Thelma, now engaged to film director Jason Gaines, who provides cash, supplies, a computer, and a vacant Palm Springs house. There, Laura and Stefan calculate coordinates for Stefan's return jaunts. Using Kokoschka's homing belt, Stefan returns to March 1944. He releases Vexxon, a deadly nerve gas, in the lab, killing everyone present. He jaunts to Winston Churchill's underground War Rooms in London, proves his credibility, and persuades Churchill to bomb the institute. He then visits Hitler's bunker, posing as a loyal officer of the SS, the Nazi paramilitary organization. He reinforces Hitler's belief that the Allied invasion will target Calais rather than Normandy, ensuring D-Day succeeds.

In the desert north of Palm Springs, where the plan calls for Laura to keep a canister of Vexxon as a contingency weapon, Stefan departs through time and Laura spots a car carrying an SS squad led by Lieutenant Erich Klietmann. Klietmann shoots Laura in the back, paralyzing her, and kills Chris. Stefan returns from 1944, finds Laura paralyzed and Chris dead, and desperately goes back through the gate. Unable to arrive earlier than his first return without creating a paradox, he writes a warning note, seals it in a beaker, and hurls it through the gate to the desert, where it materializes at Laura's feet moments after his original departure.

In the reset timeline, Laura reads the warning, grabs the Vexxon canister and her weapons, and slides with Chris into a deep arroyo, a natural drainage channel. She kills three attackers in running battles through the twisting gulch. Cornered by the last gunman, she activates the Vexxon timer; the gas kills him while she and Chris, protected by antidote capsules, survive. Stefan arrives to find them alive and weeps with relief.

Laura stonewalls the authorities for months, refusing to identify Stefan. He hides at the Gaines mansion for over a year, then moves into Laura's mountain home. She gives him a new identity and eventually invites him into her life as a partner, acknowledging she loves him, though differently from how she loved Danny. Stefan reflects that his dealings with Churchill altered the postwar world: Democracy flourishes even in Russia, with no Cold War or nuclear arms race. Years later, Laura, Stefan, Chris, Thelma (now pregnant with twins), and Jason vacation together in Monterey. Laura names the three lessons of her life: As a child she learned to endure, after Danny's death she learned to fight, and now she has learned to accept.