Three students and a school teacher disappear on an excursion to Hanging Rock, in Victoria, on Valentine's Day, 1900. The movie follows those that disappeared, and those that stayed behind, but it delights in the asking of questions, not the answering of them. Even though both the movie and the book it was based on claim to be inspired by real events, the story is completely fictional.

A young man -- starving, nearly catatonic and barely responsive -- is confined in a sanitarium. He is taken on a field trip along with other residents to the city's red-light district. There, he encounters by chance a woman from his past, triggering a series of flashbacks. We see that he was traumatized as a child, when he and his family were circus performers, and when he witnessed a murder/suicide: his father -- an American expatriate living in Mexico under suspicious circumstances -- cuts off the arms of his beloved mother, a possessive wife and religious fanatic who led a heretical church called "Santa Sangre (Holy Blood)," the members of which worshipped a martyred girl whose arms were severed by her father following her rape, and then commit suicide. Back in the present, buttressed by shock of his remembrance, he escapes the sanitarium and, in a series of hallucinations and dream-fulfillments, believes he has rejoined his armless mother. He "becomes her arms" and the "two" undertake a grisly campaign of murder and revenge.

The Mantle brothers are both doctors - both gynecologists - and identical twins. Mentally however, one of them is more confident than the other, and always manages to seduce the women he meets. When he's tired of his current partner, she is passed on to the other brother - without her knowing. Everything runs smoothly, until an actress visits their clinic, and the shy brother is the first to fall in love. Will they be able to 'share' her ?

Dennis Clegg is in his thirties and lives in a halfway house for the mentally ill in London. Dennis, nicknamed "Spider" by his mother has been institutionalized with acute schizophrenia for some 20 years. He has never truly recovered, however, and as the story progresses we vicariously experience his increasingly fragile grip on reality.

Films