Plot

A social worker, still reeling from the loss of her architect husband, investigates the eccentric, psychedelic Wadsworth Family, consisting of a mother, two daughters, and an adult son with the apparent mental capacity of an infant.

A social worker who recently lost her husband investigates the strange Wadsworth family. The Wadsworths might not seem too unusual to hear about them at first - consisting of the mother, two grown daughters and the diaper-clad, bottle-sucking baby. The problem is, the baby is twenty-one years old.—Brian J. Wright <tyrannorabbit@hotmail.com>

The social worker Ann Gentry shows interest and asks his boss to follow the mentally disabled Baby, a man that behaves like a baby, when his social worker disappears. In her first visit, she meets a dysfunctional and bizarre family, composed by his mother, Mrs. Wadsworth, and her daughters from different husbands Germaine Wadsworth and Alba Wadsworth. Ann shows a particular interest in Baby, visiting him many times and trying to improve his mental condition. Soon Germaine asks her whether she is married and Ann tells that her husband was an architect that had a car accident, and does not give any other information about her personal life. Why Ann Gentry is so obsessed by the Baby?—Claudio Carvalho, Rio de Janeiro, Brazil

Ann Gentry (Anjanette Comer) is a social worker whose husband has been injured in a car crash. She takes on the case of the twisted, mysterious Wadsworth family, and takes a special interest in "Baby" (David Manzy), a mentally ill 21-year-old who still acts and is treated like an infant by his mother and sisters. The Wadsworth clan has abused and neglected Baby, but Mrs. Wadsworth (Ruth Roman) has been extremely protective since his father left shortly after his birth, and she isn't going to let another caregiver mess with her son.

Ann tries to convince Mrs. Wadsworth that Baby can learn something, but he can't even pick up and return a ball. When his blonde sister Alba (Suzanne Zenor) hits him, frustrated by Baby's baby-like behavior, Mrs. Wadsworth defends him, herself beating Alba in turn. Physically, Baby is an attractive young man physically, and his other sister, Germaine (Marianna Hill), sleeps naked with him. Ann visits a school for "extraordinary children," sees several children play and interact together, compares it to Baby's isolation, and feels sad.

The Wadsworth sisters throw a party for some friends. Baby runs around on the dance floor and although he doesn't really fit in, none of the Wadsworth sisters' friends pay any attention to him. Mrs. Wadsworth talks about her runaway husband, and her relief that Baby will never suffer such disappointments. Ann gets dizzy after drinking a cup of punch. Alba and Germaine take her downstairs and tie her down. Baby has sex with Ann, but he doesn't seem to understand what happens. When Ann tries to release herself, Baby starts to cry. The sisters are making out with their loser boyfriends. Baby has to be bathed, and Ann dresses him up in a suit afterward. Ann takes photographs of Baby dressed as an adult, and shows them to his family.

Eventually, Ann and her mother take Baby. His family comes after them, but Ann and her mother kill them. Finally, the film reveals why Ann is so interested in Baby:

The car crash left Ann's husband with the mental capacity of an infant. Ann wanted Baby as a playmate for him. They play all day, and get along well. Two adult-size cradles appear in their decorated room.

The film ends with Ann and her two "babies" swimming in their new pool, which has been built in the backyard over the site where the bodies of Baby's mother and sisters have been buried.