Dave Miller infiltrates a sprawling estate controlled by the eccentric Dr. Fred Edison and his wife Nurse Edna, who twenty years ago fell under the influence of a sentient meteor that crash-landed nearby—an event that set them on a twisted path of kidnapping and experimentation. Dave's mission is urgent: rescue his girlfriend Sandy, who has been captured and imprisoned within the mansion's walls. Alongside a team of allies he recruits, Dave must navigate a household where nearly everyone poses a mortal threat, from the hostile human residents to the disembodied tentacles lurking in the shadows, with only a mysterious green tentacle offering any semblance of help. The mansion itself becomes both maze and death trap, where missteps lead to dungeon confinement or worse, forcing Dave to adapt his strategy as party members fall and he calls upon reserves from his group. The mansion's secrets unfold differently depending on which allies survive the ordeal and what they uncover, branching toward multiple conclusions rather than a single predetermined fate.