A large meteor explodes over the Pacific Northwest, seeding the rain clouds with a toxic alien dust. As the red rain infects anyone it touches, a family must wait out the storm and fight off the infected, intent on pulling them into the rain to become one of them.
Synopsis:India, Summer, 2001. DR. DAVID WYSOL, a scientist for the CDC, is pulled from his plane and taken to a remote fishing village by the Indian Military. The entire town has been found dead and the government wants answers. Only two people survived, a man who is now completely insane and a little boy. The boy tells Wysol that a strange red rain fell and killed everyone it touched except the insane man. That man dragged every person from their house into the rain. Wysol wants to know why the boy is immune, but before he can begin testing, the red rain starts to fall again. The troops outside die in horrible agony and the insane man breaks out of his cell and starts attacking the troops inside until the boy kills him with a soldier's gun.
Later, Wysol submits a report where he hypothesizes that the rain may contain alien bacteria from a recent meteor shower. The CDC rejects the idea but Wysol notes that the meteor shower will return again in 10 years over the Pacific Northwest...
Present day, Oregon. SOPHIE ACKNER is in the car with her parents, TYLER and LINDA, on their way to a camping trip. The car ride is tense, and we get the sense that the parent's relationship is on it's last legs. They arrive at their old, distressed log cabin to find that a new, state of the art resort has been built nearby. Run by DARE and BROOKE, it's an "off the grid" resort with no TV, phones or internet. Just you and nature. That night, Sophie takes a walk with their son, KEVIN and the two see red meteors streaking across the sky.
The next morning, Sophie gets up early and goes for a walk. Dare and a group of counsellors are working out when the red rain starts to fall. They all collapse in agony but after a minute get back up. We can see that they are different. When WANDA, the groundskeeper, asks if they're alright, they beat her to death and dump her body. They don't see Sophie, but she saw all of that.
Sophie tries to convince her parents that they all have to leave. Dare announces that the roads are now blocked by fallen trees and invites the entire camp for a hike in the rain later on. Sophie manages to convince Kevin when they see one of the counsellors bloated and dying in his bunk but it's too late to warn anyone: the rain has started.
Sophie, her dad and Kevin make it to their cabin with old couple CECIL AND EDNA. Tyler and Kevin try to find the old tractor that could take them down the mountain while the others wait. But Edna is infected with the red rain and tries to drag Sophie out into the rain. Cecil and Sophie fight her off, but she leaves and brings back Dare and the rest of the camp. Even though they're covered in sores, everyone in the rain feels blissful. They want to share this feeling with everyone inside. They drag Cecil, then Sophie into the rain. Cecil becomes one of them but dies soon after. The red rain kills people at different rates.
But Sophie is somehow immune. The rain causes no sores on her. She finds her father and Kevin hidden in a shed and offers to get the tractor. She finds the keys in the resort, where she's confronted by Dare and Brooke. They want Kevin to join them. Sophie escapes and they give chase. Kevin sacrifices himself in the rain to buy Sophie time. She gets the tractor and picks up her father and Jessica.
Three months later, Tyler drops Sophie at school for the first time since the rain. Her mother is gone along with 60% of the population in the Pacific Northwest. Tyler asks Sophie if she's ready to go back to school. For just moment, Sophie's eyes turn blood red, then she smiles and says that she's ready for everything to get "Back to normal." She heads off to class as storm clouds approach.