The protagonist is Charles Ryder (Matthew Goode), the only son of an ironically distant middle-class father (mother long dead), whom we first encounter going off to university at Oxford. Ater a very unprepossessing first encounter, he soon becomes fast friends with Sebastian Flyte (Ben Whishaw), who is both a notable member of the school's homosexual clique and the son of nobility (Lord and Lady Marchmain, played by Michael Gambon and Emma Thompson). When Sebastian takes him on a visit to the ancestral home, the magnificent Brideshead, he also discovers that the family are part of the minority Roman Catholic English nobility, and that Lady Marchmain rules the house with the kind of Papist tyranny that Elizabeth I warred against.
As portrayed in this film, mainstream British society of the time tended to view Roman Catholicism as what we would now call a "cult," and in reaction to this and centuries of religious warfare and discrimination, the Flyte family has twisted into cultic practices, a chief one being that you can't ever leave the faith--.
Although Charles resists Sebastian's wistful attempts at seduction, Charles does fall hard for Julia Flyte, Sebastian's sister. Julia frankly does not know what she wants, but by the time she decides she might want Charles, her mother has compelled her betrothal to an American (Jonathan Cake), who is a cynical fortune-hunter, but a Catholic one.
The story plays out a braid of sad tales, as Lady Marchmain's efforts to "protect" her children drive Sebastian into alcoholism and exile, immure Julia in her loveless marriage, and cause Charles to rebound into a similarly passionless marriage with a woman who mainly wants to be his artistic manager.
Uniformly nice acting by the young people leavened by veteran actors Gambon as the feckless Lord Marchmain, Greta Scacchi as his worldly mistress, and Thompson as the tyrannous Lady Marchmain.
The film has very high production values. The setting for "Brideshead" is the palatial Castle Howard in North Yorkshire ( http://www.castlehoward.co.uk )
which is the same venue used in the TV miniseries of 1981. Interestingly, despite the script's references to the beauty and desirabilty of the residence, the shooting lingers mostly on the collection of funeral-seeming statuary and a remarkably ugly "Holy Family" which is supposedly Lady Marchmain's favorite. This supports the film's theme, in which Brideshead is a mausoleum or suffocating place to be escaped from. The TV series did not have as dark a tone, and therefore showed off the glories of the property to better advantage.
Although there are no bad words, no violence, and minimal sex (rear nude shots of Charles and Sebastian are more comical than titillating-), the story and themes are for those of adult understanding, dealing as they do with desire, lust, and guilt.
Very well done for a gently paced and sad story, perhaps a good antidote for too many summer superhero movies?