Toby is born to a feral mother in the woods alongside three siblings and begins learning to survive outside.

Men arrive and trap Mother, Fast, and Toby in a culvert; Hungry is found dead and Sister escapes into the woods.

A violent dog named Spike arrives at Senora's yard, defeats Top Dog in a fight, and becomes the new pack leader.

A man declares Toby unadoptable after Spike injures his leg, and Toby is euthanized alongside Spike and two other dogs.

A woman breaks the window of a locked car to rescue a heat-stricken puppy and takes him home to her son.

An eight-year-old boy named Ethan adopts the rescued puppy, names him Bailey, and the two form an immediate bond.

Ethan befriends a new neighbor named Todd, but their friendship cools after Todd acts recklessly with fireworks.

Bailey and Ethan become stranded in the woods for days after a horse named Flare bucks Ethan off his back.

Todd sets Ethan's house on fire, and Bailey attacks Todd, biting his ankle and leaving evidence for the police.

Ethan breaks a window and jumps from the second story, landing in burning bushes with severe burns and a broken leg.

Ethan's injuries cost him his football scholarship, and he eventually leaves for college, leaving Bailey at the farm.

Police officer Jakob selects Bailey's new incarnation—a female German shepherd—names her Ellie, and trains her for search and rescue.

A man named Victor drives Bear-Bear far into the countryside and abandons him alone on the side of a road.

Ethan arrives at the shelter angry, reclaims Bear-Bear, renames him Buddy, and takes him home to the farm.

Ethan suffers a stroke on the farm and dies peacefully with Buddy lying faithfully beside him.

The story begins with Toby, a wild puppy who is captured and euthanized after a violent dog injures him and he is declared unadoptable. Reborn as a golden retriever, he is rescued from a hot car and adopted by a boy named Ethan, beginning the most important relationship of his many lives. Their bond is tested when a dangerous neighbor named Todd burns Ethan's house down, injuring him and destroying his football scholarship. After a long life on the farm, Bailey is put down and reborn as a search-and-rescue dog trained by a police officer named Jakob. Bailey's final life brings him full circle—abandoned in the countryside, he finds his way back to an aging Ethan, who dies with his faithful dog lying beside him.

Bailey's core journey across four lives and back to Ethan.

Toby's mother silently opens Senora's gate with her mouth and escapes; Toby is distracted by Senora on her porch and stays behind.

Bobby brings Sister back to Senora's yard, and Fast is overjoyed to be reunited with his favorite sibling.

Fast attacks Spike to defend Sister; Toby joins the fight, and Spike injures Toby's leg before being separated.

Todd lures Bailey to his house and attempts to glue him; Todd's sister Linda helps Bailey escape back to Ethan.

Marshmallow the neighbor's dog vanishes, and Bailey detects her scent on Todd's clothing but cannot communicate his suspicion.

Bailey mistakes Ethan's dive into a lake for drowning and drags him back to the surface, earning a scolding instead of praise.

Hannah arrives at the farm carrying a gift of brownies, and teenage Ethan reacts with obvious, flustered attraction.

Todd approaches Hannah at Ethan's football game and lies, claiming Ethan has been dating a girl named Michele Underwood.

Police follow the blood trail left by Bailey's bite on Todd's ankle and arrest Todd as the arsonist.

Bailey is left behind at the grandparents' farm when Ethan leaves for college, and Ethan and Hannah end their relationship.

Ellie and Jakob track a kidnapped girl to a remote building, where her abductor shoots Jakob before being subdued.

Maya visits the recovering Jakob at his apartment, and his story of surviving grief encourages her not to give up.

Maya pushes herself through intense physical training until she and Ellie earn their search-and-rescue certification together.

Ellie and Maya fly to an earthquake disaster site and spend hours searching collapsed buildings for survivors.

Buddy follows a yellow dog named Carly home to Hannah's house; Hannah calls Ethan after spotting his name on Buddy's tag.

Behind the headline events of Bailey's lives are the smaller moments that give them meaning—Mother's silent escape from Senora's yard, Sister's reunion with Fast, and the earliest signs of Todd's dangerous nature. As Bailey, the dog witnesses Todd's escalating cruelty toward Ethan, from luring Bailey off the street to spreading lies that nearly destroy Ethan's relationship with Hannah. Bailey's summers at the farm bring the budding romance between Ethan and Hannah, a bond Todd works to undermine and that ends painfully when Ethan leaves for college. As Ellie, Bailey survives the shooting of handler Jakob, bonds with a new handler named Maya, and helps search for survivors at an earthquake disaster. In a final life as Buddy, a chance encounter with a yellow dog leads Bailey straight back to Hannah—and through her, to Ethan.

The supporting moments and relationships that shape Bailey's many lives.

Toby's mother warns her puppies to fear humans, but Toby observes yard dogs living peacefully with people and forms his own trust.

Top Dog backs down from Fast's challenge over a bone rather than fight, revealing his fair and gentle style of leadership.

Bobby takes Toby and several packmates to the vet, where Toby is neutered and wakes wearing a confusing cone collar.

Bailey leaps onto Ethan's go-cart during a neighborhood race, giving him the win and provoking threats from Todd and his brother Drake.

Someone throws a rock through Ethan's living room window one night, and Bailey catches Todd's scent clinging to it.

Hannah confronts Ethan outside his football game, convinced by Todd's lie that Ethan has been secretly seeing someone else.

Todd sneaks to Ethan's yard after dark and leaves a piece of bitter-smelling meat near the porch that reeks of his scent.

Ellie and Jakob successfully locate an elderly woman sitting alone in a play yard, completing Ellie's first real search-and-rescue mission.

Ellie defies Maya's commands and digs into a chemical-soaked building at the disaster site, saving a trapped woman but burning her nose.

Ellie fails to track Wally's scent and loses her certification; Maya chooses to adopt her rather than send her away.

At a school classroom visit, Ellie recognizes a student's father as Jakob and sees that his once-deep sadness has completely disappeared.

Ellie dives into rushing sewer water to save a boy named Geoffrey and is later awarded a medal before a crowd.

Bear-Bear drinks from a river and suddenly understands it is the same waterway he once followed home with Ethan as Bailey.

Ethan opens a closet and shows Buddy the old collar that once belonged to Bailey, his dog from decades earlier.

Buddy fetches the flip for the dying Ethan, who looks at him and says 'Good dog, Bailey' in quiet recognition.

From his earliest life, Bailey forms his own view of humans despite his mother's warnings, watching yard dogs and deciding that people can be trusted. Small but telling revelations accumulate across Bailey's second life—sensing Todd's menace through a rock thrown in the night, catching the smell of bitter meat left near Ethan's porch, and uncovering Todd's lie to Hannah before the arson that changes everything. As Ellie, Bailey finds renewed purpose in search-and-rescue work, completing a first mission with Jakob and later saving a woman from a chemical-soaked building at the cost of her own nose. Losing her certification is a turning point, but a later school visit reveals that even the grief-stricken Jakob has found happiness again—a lesson Bailey will carry forward. In a final life, a river's familiar scent reignites Bailey's mission, and the retrieval of an old toy called the flip gives Ethan one last proof that his dog has always come back.