A quiet 1982 neighborhood is suddenly ripped out of its own time and dropped into a prehistoric nightmare. As dinosaurs overrun Oak Street, the Platt family must survive deadly creatures, find a way home, and confront the cracks already forming inside their family.
A Normal Summer Night on Oak Street
The story begins in 1982 in the quiet neighborhood of Flowervale, where residents are enjoying a lively block party on Oak Street. Among them is the Platt family: parents Denise and Greg (Anne Hathaway and Ewan McGregor), their children Audrey and Brian (Maisy Stella and Christian Convery), and the family dog, Starbuck. 
On the surface, the Platts appear to be an ordinary suburban family, but Audrey and Brian have already noticed that their parents have been arguing more than usual. Greg works as a pizza delivery driver and believes Denise is embarrassed by his job, while Denise is determined to finish her manuscript and pursue her dream of becoming a published novelist.
Strange Signs Begin to Appear
Denise confides in her elderly neighbor, Mrs. Huddleston (Anne Gee Byrd), about her writing ambitions. Soon afterward, she helps Mrs. Huddleston remove a strange plant that has suddenly appeared in the yard. Neither woman realizes that the plant is the first sign that something impossible is beginning to happen on Oak Street.Meanwhile, Brian spends time wandering the neighborhood with his friends while trying to avoid an older boy whose younger brother was accidentally injured by Brian. During their walk, the boys notice a new girl named Jeanette Christiansen (Jordan Alexa Davis), who has recently returned from private school.
Elsewhere, Denise is forced to deal with their irritating neighbor Mel (PJ Byrne), who complains that Starbuck has been using his yard as a bathroom.
The First Mysterious Light
That night, an intense flash of light appears outside the Platt home. Starbuck begins barking, prompting Brian to investigate, but he finds nothing unusual. By morning, however, Mel angrily accuses the family of playing a prank on him after discovering an enormous pile of feces in his backyard.Greg insists that his children had nothing to do with it, but reluctantly agrees to help Mel clean up. Denise, increasingly suspicious of the strange plant from Mrs. Huddleston’s yard, visits the local library in an attempt to identify it.
A Storm Changes Everything
The following night, a violent storm sweeps through Flowervale. Another bright flash erupts across the neighborhood, knocking out the power and flooding the Platts’ basement. While the family struggles to light the house, they hear terrifying screams outside.Greg goes to investigate, but the street appears empty. By the next morning, Starbuck has disappeared, and Greg and Denise begin searching the neighborhood for him.
From the roof of the house, Audrey sees a cat in the street and suddenly hears it being attacked by something hidden nearby. She races to Brian’s room, where the siblings catch sight of a huge tail disappearing into the bushes.
The Dinosaurs Arrive
Denise enters Mrs. Huddleston’s house and makes a horrifying discovery: her neighbor has been killed, her throat torn open by an unknown animal. Bloody footprints lead outside, where Denise finds that the backyard is now covered with prehistoric vegetation.At the same time, Greg spots a theropod moving between the houses. The dinosaur quickly notices him and gives chase, forcing Greg to run for his life. Denise arrives just in time and shoots the animal with Mrs. Huddleston’s rifle.
Their relief lasts only seconds. More theropods appear and begin attacking residents throughout the neighborhood. Greg and Denise rush back to the house, where Audrey and Brian let them inside before the family attempts to escape by car.
Oak Street Has Been Transported to Another World
The Platts soon realize that escape is impossible. Their entire neighborhood has somehow been transported into a vast prehistoric landscape filled with dinosaurs and unfamiliar plant life. There are no normal roads leading away from Oak Street, and dangerous creatures roam beyond the houses.With no other option, the family returns home and barricades the windows and doors. They try to find a radio signal, but receive no useful information. Audrey, fascinated by science and the work of Carl Sagan, suggests that a wormhole may have transported the neighborhood to another point in time.
Greg attempts to reassure everyone that they will survive, even though he has no idea how they are going to escape.
The Neighborhood Falls Apart
That evening, the family watches in horror as Mel climbs onto his roof and begins shooting at a flock of pterosaurs. The creatures swarm him and tear him apart.Inside the Platt home, the pressure of the situation reignites the tension between Greg and Denise. Greg accuses Denise of wanting to leave the family after reading part of her manuscript, while Denise struggles to explain what she truly wants from her life.
While his parents argue, Brian spots Starbuck outside and sneaks away to rescue him. Audrey notices her brother leaving and follows. When Greg and Denise realize both children are gone, they immediately head into the dangerous streets to find them.
Brian and Audrey Find Jeanette
Brian soon encounters a gigantic worm-like creature before being confronted by the older boy who has been threatening him. The teenager attacks Brian in revenge for injuring his younger brother and nearly goes too far before his brother begs him to stop.The older boy finally backs down, admitting that he is terrified by what is happening around them. Brian escapes and is soon reunited with Audrey.
The siblings later discover Jeanette, who has lost her parents during the dinosaur attacks. When a theropod corners them, Audrey manages to stab the creature and save the group. With nowhere else to go, Jeanette joins the Platt children.
Greg and Denise Discover a Way Home
Greg and Denise continue searching for their children while navigating streets filled with prehistoric animals. After carefully driving around a group of harmless dinosaurs, they are attacked by a massive Spinosaurus.The creature smashes their vehicle into a house, starting a fire. Greg and Denise barely escape and then narrowly avoid being trampled by a stampeding herd.
During their escape, they discover something extraordinary inside another house: a wormhole that appears to lead back to 1982. They finally have a way home, but their children are still missing.
Rather than abandon Audrey and Brian, Greg and Denise turn away from the portal and continue searching. Moments later, the wormhole closes.
The Family Reunites — and Tragedy Strikes
The following day, Greg and Denise finally find Audrey, Brian, and Jeanette sheltering inside another house. By now, the fire from the previous night has spread across the prehistoric landscape, making the situation even more dangerous.The group continues on foot until an Allosaurus spots them and attacks. Denise draws the dinosaur away from the children by firing at it, but the creature corners her on a porch.
Greg charges in with a sledgehammer and manages to knock the Allosaurus down, saving Denise. Tragically, he becomes distracted for just a moment. The dinosaur recovers and brutally kills him.
Denise and the children can do nothing but watch in shock before forcing themselves to keep moving.
A Final Wormhole Appears
Now devastated by Greg’s death, Denise leads Audrey, Brian, and Jeanette through the burning neighborhood. Eventually, they notice a mysterious glow coming from a house on a hill and realize that another wormhole may have opened there.They arm themselves and head toward the house, which belongs to librarian Mrs. Valcourt (Emily Kuroda). Inside, the group is cornered on a stairwell by a pack of rauisuchians.
Mrs. Valcourt suddenly appears and shoots one of the creatures, giving Denise and the children a chance to escape. Unfortunately, the remaining animals attack and kill her.
The enormous worm-like creature from earlier then moves toward the children, but Denise repeatedly stabs it until it retreats.
Starbuck Returns at the Perfect Moment
The survivors finally reach the roof, where the wormhole appears within jumping distance. They have only moments to time their escape correctly.Jeanette jumps first and successfully passes through the portal. Brian attempts to follow but misses and falls to the ground below. Pterosaurs immediately swoop down toward him.
Just when it appears Brian is finished, Starbuck suddenly returns. The dog attacks one of the pterosaurs and distracts it long enough for Denise and Audrey to pull Brian back to safety.
With Starbuck finally reunited with them, Denise, Audrey, and Brian jump through the wormhole before the dinosaurs can reach the roof.
They Return to 1982 — Twenty Minutes Before Disaster
The family lands in a swimming pool back in 1982. However, they quickly realize they have not returned to the exact moment they disappeared. They have arrived approximately twenty minutes before the mysterious event that transported Oak Street into the prehistoric world.After reuniting with Jeanette, they discover that they are on a hill overlooking the neighborhood. There is not enough time to reach Oak Street and warn everyone in person.
Denise uses a payphone to call as many neighbors as possible and urges them to leave immediately. She then comes up with a way to save Greg: she orders a pizza delivery to their location.
Greg arrives, completely unaware of what his family has already experienced. Denise, Audrey, and Brian embrace him emotionally. Moments later, they witness the familiar flash of light from a safe distance as Oak Street is swallowed by the prehistoric phenomenon.
Ending Explained: Denise Changes the Future
Two years later, the consequences of the Oak Street incident are still being studied. The military has sealed off the affected area, capturing or killing many of the prehistoric creatures while scientists continue investigating how the time displacement occurred.Because Denise was able to warn the neighborhood before the event, several people who died in the original timeline are now alive, including Mrs. Huddleston, Mrs. Valcourt and her husband, and even Mel.
Most importantly, Greg survives. By returning twenty minutes before the disaster and calling him away from Oak Street, Denise prevents the death she witnessed in the prehistoric timeline.
Jeanette’s parents also survive, meaning she no longer has to grow up without them.
Denise Finally Becomes a Published Author
The experience also changes Denise’s life in another way. She finally completes and publishes her book, titled The End of Oak Street, which tells the extraordinary story of what happened to the Platt family and their neighborhood.The book represents more than professional success. It shows that Denise has finally found a way to pursue her own dream without abandoning her family. At the same time, the Platts have become much closer after everything they endured together.
The Final Scene
The film closes with the Platt family gathering for a barbecue. Jeanette and her parents are there as well, now part of the family’s extended circle.What began as a story about a fractured household ends with the Platts more united than ever. They survived dinosaurs, a prehistoric nightmare, and the loss of Greg in one timeline — only to be given a second chance to change the outcome.