Spider Baby or, the Maddest Story Ever Told (1967) Spoiler-Free Summary – What It's About

At the decaying Merrye House — a place locals have learned to fear — three siblings live in peculiar seclusion with their family chauffeur, Bruno. Long after their parents' death, Bruno remains a devoted guardian, honoring a promise to protect Ralph, Virginia, and Elizabeth from a world that would never understand them. The children suffer from Merrye Syndrome, a rare hereditary condition unique to their bloodline, one that causes those afflicted to regress — mentally and physically — as they age, pulling them backward down an imagined evolutionary ladder. The result is an unsettling blend of innocence and primal unpredictability.

Bruno works tirelessly to maintain a fragile equilibrium within the household, shielding the siblings from outside interference and keeping their condition hidden from prying eyes. Yet the children's increasingly erratic behavior tests even his boundless patience and loyalty. Virginia's eccentricities, Ralph's childlike nature, and Elizabeth's sharp wit all demand careful management, and Bruno's gentle authority is sometimes the only barrier between his charges and consequences neither fully comprehend. The mansion itself becomes a character in its own right — crumbling, secretive, and filled with hidden corners where reality and delusion blur together.

The family's carefully preserved isolation faces an unexpected threat when distant relatives arrive with legal entourage in tow, claiming rights to the property and raising questions about guardianship and propriety. Bruno's determination to keep the children out of institutions and away from scrutiny clashes with the newcomers' suspicions. As the visitors settle in for what should be a simple overnight stay, the atmosphere shifts — the house's peculiar rhythms grow harder to disguise, and the line between eccentricity and menace begins to dissolve in ways both darkly comic and deeply unsettling.

What follows is a bizarre, tension-filled evening where civility masks ulterior motives, and long-buried family secrets strain against the weight of exposure. The film weaves horror and humor into an experience that feels like a fairytale gone wrong, where nothing is quite as it seems, and innocence may be the most dangerous disguise of all.