On October 30, 1977, Jerry Goldsmith, Bill Hudley, Mary Knowles, and Denise Willis are on the road in hopes of writing a book on offbeat roadside attractions. When the four meet Captain Spaulding, the owner of a gas station and "The Museum of Monsters &amp; Madmen", they learn the local legend of Dr. Satan. As they take off in search of the tree from which Dr. Satan was hanged, they pick up a young hitchhiker named Baby, who claims to live only a few miles away. Shortly after, the vehicle's tire bursts in what is later seen to be a trap and Baby takes Bill to her family's house. Moments later, Baby's half-brother, Rufus, picks up the stranded passengers and takes them to the family home.
There they meet Baby's family: Mother Firefly, Otis Driftwood, her adopted brother, Grampa Hugo and Baby's deformed giant half-brother, Tiny. While being treated to dinner, Mother Firefly explains that her ex-husband, Earl, had previously tried to burn Tiny alive, along with the Firefly house. After dinner, the family puts on a Halloween show for their guests and Baby offends Mary by flirting with Bill. After Mary threatens Baby, Rufus tells them their car is repaired. As they leave, Otis and Tiny, disguised as scarecrows, attack the couples in the drive way and take them prisoner. The next day, Otis kills Bill and mutilates his body for art. Mary is tied up in a barn, Denise is tied to a bed while dressed up for Halloween, and Jerry is partially scalped for failing to guess Baby's favorite movie star.
When Denise doesn't come home, her father Don calls the police to report her missing. Two deputies, George Wydell and Steve Naish, find the couples' abandoned car in a field with a tortured victim in the trunk. Don, who was once a cop, is called to the scene to help the deputies search. They arrive at the Firefly house and Wydell questions Mother Firefly about the missing teens. Mother Firefly shoots Wydell in the neck and kills him, and Don and Steve are then killed by Otis upon finding other bodies in the barn. Later that night, the three remaining teenagers are dressed as rabbits, and taken out to an abandoned well. Mary attempts to run away, but is stabbed to death by Baby moments later.
Meanwhile, Jerry and Denise are lowered into the well, where a group of undead men pull Jerry away, leaving Denise to find her way through an underground lair. As she wanders through the tunnels, she encounters Dr. Satan and a number of mental patients; Jerry is on Dr. Satan's operating table being vivisected. Dr. Satan tells his mutated assistant, who turns out to be Earl, Mother Firefly's ex-husband, to capture Denise, but Denise outwits him and escapes the chambers by crawling to the surface. She makes her way to the main road, where she encounters Captain Spaulding, who gives her a ride in his car. She passes out from exhaustion in the front seat, and Otis suddenly appears in the backseat with a knife. Denise later wakes up to find herself strapped to Dr. Satan's operating table, with Dr. Satan standing there.
What House do they go to and question Mother Firefly?
Firefly house