THE ALLIGATOR PEOPLE

After being administered the drug sodium pentothal by two psychiatrists, amnesiac nurse Jane Marvin recalls a series of events from her repressed memories when she was known as Joyce Webster.

In flashbacks, we see Joyce after marrying a young man named Paul Webster. Aboard their honeymoon train, Paul receives a telegram and leaves in a panic to make a phone call. When the train pulls out, Paul is missing, having vanished without a word. Throughout the following months, Joyce employs private detectives and searches for her husband. She eventually finds a lead: the address of the Cypresses Plantation that Paul entered on his college enrollment forms.

Joyce travels to the desolate town of Bayou Landing, Louisiana. There, she meets Manon, a handyman at the Cypresses, and convinces him to drive her to the plantation. Joyce then introduces herself to Lavinia Hawthorne, the Cypresses' stern mistress. When Joyce suggests that Paul once lived there, Lavinia calls her a liar and tries to have her thrown out. However, after learning that Joyce has missed the last train back to town, Lavinia reluctantly invites her to stay the night under the proviso that she must not leave her room.

That night, Joyce hears the strings of a piano and slips out of her room to investigate. Downstairs, she sees a man in a trench coat seated at the piano. The shadowy figure turns out to be Paul, mutated and reptilian-looking. When Joyce enters the room, Paul flees. He later insists to Lavinia that Joyce must leave as soon as possible. The next morning, Mark, the local doctor, comes to the house to question Joyce. Sensing that everyone is withholding information about Paul, she refuses to leave. When Joyce demands that Lavinia tell her what she did to Paul, the older woman breaks down and confesses that he is her son.

Joyce later sees Paul again and follows him into the swamps. After being menaced by several alligators and a giant snake, Joyce is rescued by Manon, who carries her to his shack. There, he assaults her until she gets knocked unconscious. An outraged Paul then bursts in and fights Manon. After a struggle, Paul manages to incapacitate him and takes Joyce back to the house. Manon recovers and vows to kill Paul. Back at the house, the maid Lou Ann is caring for Joyce while Paul presses Mark to give him an untested cobalt treatment in hopes of curing his condition. Mark agrees to give him the treatment.

The next morning, Mark summons Joyce to his lab and tells her about his experiments with reptilian hormones that are capable of regenerating limbs. After Paul was horribly mangled in a plane crash, Mark administered the serum to him and several other accident victims. The treatment appeared to be a great success, until his patients began to take on reptilian traits. After Paul received the telegram notifying him of this, he hurriedly left the train and came home in hopes of reversing his condition. When Joyce learns of Paul's upcoming cobalt treatment, she insists on being present.

Paul encounters Joyce at the clinic and feels ashamed, but she reassures him of her love. When they start the treatment, Manon bursts into the lab and destroys the control panel. The machine starts shooting powerful rays at Paul that transform him into a bipedal, reptilian monster with an alligator-like head. While trying to attack Paul, Manon gets caught on some cords and is electrocuted. Confused, Paul tries to communicate, but his voice has been replaced with a reptilian snarl. Hearing his wife and mother scream in horror, Paul flees into the swamps. Joyce runs after him, as the cobalt machine short circuits, self-destructs and destroys the lab. Scrambling away from his wife, Paul stumbles into quicksand and slowly sinks out of sight, seemingly meeting his demise.

Back in the present, the psychiatrists review the tapes of Joyce's ordeal. Concluding that her amnesia has allowed her to suppress the horror and resume a normal life, they decide not to tell her about her past.

Joyce ultimately learns the fate of her husband Paul, discovering the horrific results of scientific experiments that transformed him into a mutant. The ordeal concludes with the resolution of Joyce's memories and the revelation of the tragic consequences of the plantation’s experiments.

The ending ties together the film’s themes of memory, loss, and the dangers of unchecked scientific ambition. Joyce’s recovered memories serve as both closure for her personal trauma and a cautionary tale about the consequences of tampering with nature. The narrative’s return to the present underscores the lasting psychological scars left by her ordeal.