Description
A military satellite crashes near Arborville, California. An elderly transient discovers, within the sphere, a slime mold-like substance that adheres to his hand. Three high school students, Brian, Meg and Paul, take him to a hospital. After Brian leaves, Paul witnesses the lower half of the transient melting from exposure to the Blob. As he calls for help, the Blob drops on top of him. Meg walks in to see Paul being consumed by the growing Blob. While she tries freeing him, his arm dissolves off, Meg is thrown against a wall and knocked unconscious, the Blob fully dissolves Paul, and the Blob oozes out of the hospital, where it devours Scott, Paul\'s friend and his date Vicki nearby.
After Brian and Meg have unsatisfactory encounters with the police, they meet at a diner where Meg tells Brian about the Blob. Brian\'s disbelief is shattered when a diner worker is violently pulled through a sink drain by the Blob. It pursues them to the diner\'s walk-in freezer, but the Blob retreats after entering the freezer. After consuming Sheriff Geller and the diner\'s owner Fran Hewitt, the Blob reenters the sewers, observed by the town\'s Reverend Meeker, who investigates inside the diner and picks up a few frozen fragments of the Blob, placing them inside a glass jar. Meg and Brian return to the police station, where the dispatcher tells them Deputy Briggs is near the meteor-landing site. They discover a military operation led by a scientist, Dr. Meddows, who orders the town and the two teens quarantined. While Brian escapes, Meg is taken to town where she learns her younger brother, Kevin, is missing. Meg learns he and his friend, Eddie, sneaked into the movie theater. The Blob enters the theater though the ventilation shaft, where it begins to feed on the staff and audience. Meg arrives as the audience flees the theater, rescuing Eddie and Kevin, but the trio are cornered in an alleyway when trying to escape and are forced to flee into the sewers.
Brian eavesdrops on Meddows and Jennings talking and learns that the Blob is a biological warfare experiment created during the Cold War, launched into space because it was so dangerous. Learning that the Blob has entered the sewers, Meddows decide to trap it there, even if that means allowing Meg, Kevin, and Eddie to die. Brian is discovered listening in and evades military personnel by driving his motorcycle into the sewers. Meanwhile, Meg and Kevin flee from the Blob when it emerges and consumes Eddie. Kevin escapes by scaling a pipe to the surface, and Meg is saved by Brian. They escape the sewers to the town square, where Brian confronts Meddows in front of the townsfolk and Briggs. When Brian begins to win over Briggs with his arguments, Meddows attempts to shoot Brian, but is killed by the Blob when it drags him into the sewer. The military unload their weapons in the sewer entrance in hopes of killing the creature, but only succeed in making it enraged. The Blob suddenly bursts out of the sewer, rampaging down the street and feasting on the town\'s population. Reverend Meeker proclaims the scene to be the prophesied end of the world, after which a failed flamethrower attack on the Blob sets him ablaze. Meg saves him with a fire extinguisher, and in the process blasts the Blob with it. When the monster backs off, she realizes that the Blob cannot tolerate cold.
The survivors retreat to the town hall and hold the Blob off with furniture-barricades and fire extinguishers, but it is a losing battle; the Blob engulfs half the building and devours Briggs. Brian goes to the town\'s garage and gets a snow maker truck that has canisters of liquid nitrogen attached. Brian shoots snow at the creature, angering it, and it leaves its attack on the town hall and rams the truck, knocking the canisters onto the street. As the Blob attempts to break into the overturned truck with Brian inside, Meg lures it away from him toward the canisters, which she has rigged with an explosive charge taken from a dying soldier. She tries getting clear, but snags her foot between two pieces of metal, trapping her. Brian frees himself from the truck and rescues Meg. The Blob is about to overrun them when the charge goes off, blowing up the canisters and covering the Blob in liquid nitrogen. The creature is flash-frozen into a mass of crystallized pieces. Moss Woodley has its remains stored in the town ice house.
Later, at a tent-meeting church service in a field, Meeker, disfigured by his burns, preaches a doomsday sermon resembling the Blob\'s attack. He has a still-living piece of the Blob, trapped inside the jar, and hints at planning to unleash it back upon the world when God gives him a sign.
