Description
Set in contemporary England, the film follows Dr. Brockton (Joan Crawford), a renowned anthropologist who learns that in the caves of the countryside a lone male troglodyte is alive and might be able to be helped and even domesticated. In the interest of science and the potential groundbreaking discovery of the missing link, she gets the creature to the surface; and while the rest of the townsfolk and police scatter in terror, Brockton stands steady with her tranquilizer gun and stuns the caveman into submission. She brings him back to her lab for study, but runs into trouble as a few people oppose the presence of a "monster" in the town, especially Sam Murdock (Michael Gough), a local businessman who is not only afraid of the negative commercial consequences but is also suspicious of a woman heading a research facility. In the meantime, the creature, given the name of "Trog", is taught by Brockton to play and share; and the capacity for language is induced by a number of surgeries and a mysterious hypnotic device that causes Trog to see or relive his distant past, including clashes between various dinosaurs.
Still disturbed by Brockton's experiments, and enraged at a municipal court's decision to protect Trog, Murdock releases Trog in the middle of the night, hoping the caveman will be confronted and killed by either local residents or well-armed authorities. His plan ultimately succeeds. After being released, Trog wanders into town and kills the first three people he meets (a grocer, a butcher, and a citizen in a car), but not before he beats Murdock to death. Trog then snatches a little girl from a playground and takes her to his cave. Dr. Brockton, the police, and army personnel soon gather at the cave's entrance. After pleading fruitlessly with the authorities to let her reason with Trog and safely retrieve the girl, Brockton suddenly acts on her own and charges down into the cave, where she finds the girl cowering in a corner. Trog initially behaves aggressively at the sight of the doctor in his refuge, but after a stern reprimand and a plea by Brockton, Trog surrenders the girl to her. Shortly after the doctor and girl exit the cave, all of Brockton's work on behalf of science is shattered when soldiers ignite explosives before assaulting the cave. Trog is quickly wounded in a barrage of gunfire, falls, and is impaled on a stalagmite. The film then ends with an on-site news reporter asking the doctor to comment on the death of the missing link, but Brockton is either unwilling or unable at that moment to express her profound disappointment and grief over the loss of Trog, so she simply pushes aside the reporter's microphone and slowly walks away from the scene by herself