Anne-Marie Martin

Kate Cooper, haunted by a devastating encounter with a tornado during her college years, studies storm patterns on screens safely in New York City. She is lured back to the open plains by her friend, Javi to test a groundbreaking new tracking system. There, she crosses paths with Tyler Owens, the charming and reckless social-media superstar who thrives on posting his storm-chasing adventures with his raucous crew, the more dangerous the better.

In June 1969, a family that includes a five-year-old girl called Jo seeks shelter in a storm cellar as a powerful tornado strikes. The storm is so strong that the locks on the cellar door fail, and Jo's father is caught up in the storm and killed. Jo and her mother emerge from the cellar the next morning to find a devastated landscape. Their home is utterly destroyed. 27 years later, Jo (Helen Hunt), who is now a meteorologist leading a team of storm chasers. Geostationary Operational Environmental Satellite track the tornado activity across the nation. GOES satellites are a collaborative program between NASA and NOAA that provide data and imagery on atmospheric conditions and solar activity. Jo manages her own equipment to track tornadoes on the ground, however she is running out of grant money. Her crew includes Dusty (Philip Seymour Hoffman), Rabbit (Alan Ruck), Joey (Joey Slotnick) and others. Jo is reunited with her estranged husband, Bill Harding (Bill Paxton), who is a former weather researcher and storm chaser who has since become a weather reporter. He is planning to marry sex therapist Melissa Reeves (Jami Gertz) and arrives at Jo's field station for her signature for the final divorce papers. Jo is excited about the weather, with NSSL predicting the biggest series of storms lined up one after the other. Bill realizes that Jo has not signed one page of the papers. Jo shows Bill the realized "Dorothy", a device containing hundreds of small weather sensors that he conceptualized. Dorothy could revolutionize tornado research and potentially provide an earlier storm-warning system, but the device must be deployed dangerously close to a tornado to work. Dorothy is designed to take measurements from inside a tornado funnel and provide insights into how a tornado works. Jo's team rushes off to chase a developing storm with her failing to sign the papers, forcing Bill and Melissa to follow. The team encounters Dr. Jonas Miller (Cary Elwes), a smug and sponsored meteorologist and storm chaser. Miller is a rival storm chaser and former colleague with corporate funding, has stolen his idea for his own Dorothy-like device, Dot3, with plans to deploy it first and claim credit for its design. Enraged, Bill agrees to accompany Jo and the team for one day to launch Dorothy. Tensions rise between Jo and Bill when they have several dangerous encounters with tornadoes as the team tries unsuccessfully to deploy the new device. As the team pursues a developing tornado, Bill drives Jo's truck into a ditch, attempting to get in front of the damage path. However, the tornado strengthens into an F2, and after destroying a barn, it corners the truck in front of a bridge. Jo and Bill shelter under the bridge as the tornado destroys the vehicle and one of the four Dorothy prototypes. They continue chasing in Bill's truck, with Melissa in the back. They find a second tornado and head off on a back-road when it shifts its track. They soon find themselves driving through heavy rain and before long the same storm drops satellite tornadoes onto a lake. The team follows the F2 now with a group of waterspouts on Kaw Lake, and one of them develops another vortex, which spins the truck around before disappearing. Jo and Bill are elated by the thrill, but Melissa becomes traumatized in the process. They have lunch with Jo's aunt Meg (Lois Smith) at Wakita, Oklahoma. Dusty, a member of Jo's team, tells stories about Bill's crazy past career as a storm chaser to Melissa, but Bill claims that he had killed his old personality. The chasers take off to chase yet another storm. As they track the storm, they learn the tornado is on the ground, but they have trouble finding it. Approaching a hill, they run into a hailstorm, and Jo drives ahead of the chasers to intercept the oncoming tornado. Jo and Bill intercept an F3 with unpredictable movements, and it soon knocks over power-lines that crush Dorothy II. With the truck damaged, Bill forces them to retreat, but Jo undergoes an emotional breakdown over the failure, and unloads about her motivations and her father's death. Bill admits his feelings for Jo, unaware that Melissa is overhearing them through the CB radio. The team overnights in Fairview to repair their vehicles, while Jo signs the papers. A nocturnal F4 wedge tornado unexpectedly appears, and it forces the team and others into a garage pit near a drive-in theater for protection. The tornado destroys the garage and two team vehicles as the result of tossed debris and injures several people before proceeding toward Wakita. Melissa, frightened by the dangers of storm chasing and recognizing the unresolved feelings between Jo and Bill, leaves. The tornado moves on and hits Wakita, devastating the community and injuring Meg. Bill and Jo rescue Meg from her collapsing house. The National Severe Storms Laboratory (NSSL) forecasts that a potentially record-breaking tornado will form the next day. Inspired by Aunt Meg's wind-vane sculptures, Bill and Jo add aluminum "wings" to the last two Dorothy prototype sensors, making them more aerodynamic. True to the forecast, a mile-wide F5 tornado forms the next day, and the team pursues it. Bill and Jo attempt to place Dorothy III in its path; however, the device is knocked over and destroyed by an airborne tree. Meanwhile, Jonas attempts to deploy Dot3, ignoring Bill and Jo's warnings that the tornado is changing direction and headed straight at them. The tornado sweeps Jonas's truck away, killing him and his driver. With the last remaining Dorothy affixed to the truck bed, Bill and Jo drive directly at the tornado, then jump out, sacrificing Bill's truck to ensure that Dorothy IV can release its probes into the wedge. The gamble is successful, as Dorothy IV's probes provide immediate scientific data, but without their truck, Jo and Bill are forced to run as the tornado shifts toward them. Inside a nearby pump-house, they strap themselves to deep pipes. As the building rips away, the F5's core passes over them. After the tornado dissipates, the team celebrate their success and Jo and Bill reconcile.

It is 1985. Police Sgt. Jack Ramsay is 35 years old; his records show he was born in 1950. He is a widower and has a 10-year-old son Bobby. He works in a large city which is never specified. Ramsay has a fear of heights, so he asked to be moved to a division called "Runaways" that deals with malfunctioning robots, who have taken over many of the jobs humans once did. Thompson is Ramsay's new partner. She has tried other jobs, including computer programmer, but none of them worked out. She is pretty but capable. On their first assignment together, Ramsay and Thompson must take a helicopter to a farm where pest-control robots are out of control. They are able to successfully capture the robots. On their second assignment, Ramsay and Thompson go to the house of a man named Johnson whose household robot has killed two people. A 10-month-old baby is alone and crying. TV crews are on the scene and Ramsay must discourage them, but one cameraman insists on going inside and gets killed before Ramsay can bring the robot under control. Johnson comes home and is very concerned about the baby but disappears before Ramsay can rescue the baby. A suspicious looking man is watching everything. Ramsay goes home to Bobby and Lois, the robot who takes care of the house and Bobby. Bobby, who should be in bed, is very excited about what he has just seen happen on TV, and he likes Thompson, who is already showing signs of being a partner to Ramsay in more than one way. Lois makes sure Bobby goes to bed and asks if Thompson needs to be entered into her list of information, which of course she does. On another day, Ramsay and Thompson go out on another assignment, this one a tall building under construction where a robot is throwing items off the building. Ramsay gives this job to Thompson and he stays on the ground. Johnson is discovered staying in a hotel room, and Ramsay and Thompson go to pick him up. Johnson fears for his life, with good reason. His company developed a new technology that someone called Dr. Luther wants to use to commit crimes. Just before Ramsay can take Johnson to the station, he takes off running and Ramsay chases him. Dr. Luther joins the chase and starts firing bullets at Johnson, only these are not ordinary bullets. They an go around corners and dodge obstacles and have the ability to track their target. After several attempts, Johnson is killed. Although it is not Ramsay's department, he continues to investigate the case and discovers Dr. Luther in a room at the Ritz hotel. There is gunfire and several officers are killed. TV crews are there as well. Despite his fear of heights, Ramsay must go to the roof to rescue a girl being held by Dr. Luther. Because of all the chaos and the deaths, and the fact it wasn't his department, Ramsay is reprimanded by his Chief. There is an incident at the company where Johnson worked, and secretary Jackie is being held prisoner by one of the robots. Ramsay rescues Jackie and destroys the robot in the process, which the security guard says wasn't necessary. Ramsay takes Jackie and offers her protection. She has the templates necessary for the chips needed for Dr. Luther's special bullets, and Dr. Luther still wants them. This leads to a car chase where special robots that can track Jackie start shooting. Eventually Ramsay and Jackie have to change cars; a robot is driving theirs and Thompson is in the other. As soon as the transfer is made the car they were in is blown up. At a nice restaurant with outdoor seating Dr. Luther demands Jackie be turned over to him. Jackie leaves part of what he wants behind as insurance, but he kills her when he realizes he doesn't have everything. Dr. Luther escapes and ends up at Ramsay's precinct dressed as a cop, and no one notices. He has an eyeball which is capable of passing a retinal scan that is required to sign in to Ramsay's computer. Ramsay later sees information about him on the screen, and he knows someone knows where he lives. He goes home and discovers Lois seriously damaged and Bobby missing. After fixing Lois, Ramsay goes to a tall building under construction where Bobby is being held. After going up in the elevator, Ramsay demands Bobby be released and then hands over the templates. Dr. Luthor explains that as soon as Bobby gets off the elevator, robots called spiders will kill him because there can be no witnesses. Thompson has followed Ramsay and rescues Bobby before anything can happen to him, but Ramsay experiences a series of terrifying events before he can successfully trick Dr. Luther into the trap his set for Bobby, leading to Dr. Luther's death. At the end of the movie it is clear Ramsay and Thompson are romantic partners.