Description
In a small rural Pennsylvania town in July 1957, teenager Steve Andrews (Steven McQueen) and his girlfriend, Jane Martin (Aneta Corsaut), kiss at a lovers\' lane when they see a meteorite crash beyond the next hill; Steve decides to look for it. An old man (Olin Howland) living nearby finds it first. When he pokes the meteorite with a stick, it breaks open, and a small jelly-like globule inside attaches itself to his hand. In pain and unable to scrape or shake it loose, the old man runs onto the road, where he is nearly struck by Steve\'s car; Steve and Jane take him to Doctor Hallen (Stephen Chase).
Doctor Hallen anesthetizes the man and sends Steve and Jane back to locate the impact site and gather information. Hallen decides he must amputate the man\'s arm since it is being consumed. Before he can, the Blob completely consumes the old man, then Hallen\'s nurse Kate, and finally the doctor himself, growing redder and larger with each victim consumed. Steve and Jane return in time for Steve to witness the doctor trying to get out the window with the creature covering him. They leave and go to the police station and return with Lieutenant Dave (Earl Rowe) and Sergeant Bert (John Benson). There is no sign, however, of the creature or its victims, and the sceptical Bert dismisses Steve\'s story as a teenage prank. Steve and Jane are taken home by their parents, but they later sneak out.
In the meantime, the creature consumes a mechanic at a repair shop. At the Colonial Theater during a midnight screening of Daughter of Horror, Steve recruits Tony (Robert Fields) and some of his friends to warn people about the creature. When Steve notices that his father\'s grocery store is unlocked, he and Jane go inside to check why. The janitor is nowhere to be seen. The couple is quickly cornered by the creature and they seek refuge in the walk-in freezer. The creature oozes in under the door but quickly retreats. Steve and Jane gather their friends and set off the town\'s fire and air-raid alarms. The responding townspeople and police still refuse to believe them. Meanwhile, the creature enters the Colonial Theater and engulfs the projectionist before oozing into the auditorium. Steve is finally vindicated when screaming people flee the theater in blind panic.
Jane, her kid brother Danny, and Steve become trapped in a diner, along with the manager and a waitress, as the creature, enormous from the people it has consumed, engulfs the diner. Dave has a connection made from his police radio to the diner\'s telephone upstairs, telling those in the diner to get into the cellar before the police bring down a live power line onto the creature.
When the power line is felled, it discharges a massive electrical current into the creature which is unaffected but the diner is set ablaze. When the diner manager uses a carbon dioxide extinguisher on the fire, Steve notices that the creature recoils. Steve remembers that it also retreated from the freezer, telling Jane \"That\'s why it didn\'t come in the ice box after us. It can\'t stand cold!\" Shouting in hopes of being picked up on the open phone line, Steve yells to Dave about the creature\'s vulnerability to cold. The firemen have a limited supply of CO2 fire extinguishers. Jane\'s father, high school principal Henry Martin (Elbert Smith), leads Steve\'s friends to break into the school to retrieve all its CO2 extinguishers. On their return, a brigade of fire extinguisher-armed students, firemen and police first drive the creature away from the diner freeing all trapped there, then surround and freeze the creature.
Dave requests authorities send an Air Force heavy-lift cargo aircraft to transport the creature to the Arctic. Dave says that while the creature is not dead, at least it will be stopped. To this, Steve replies, \"Yeah, as long as the Arctic stays cold\". The film ends with parachutes bearing the creature on a pallet down to an Arctic ice field with the superimposed words \"The End\" morphing into a question mark.
