A tale of two squabbling siblings forced to look after their incontinent father in his twilight years is not the stuff of belly-laughs.

Yet director Tamara Jenkins has woven a touching, honest and often laugh-out-loud drama around the grim predicament the reluctant brother and sister find themselves in.

It helps that stellar talents Laura Linney and Philip Seymour Hoffman take the roles of estranged forty-somethings Wendy and Jon.

She is a struggling East Village playwright forced to take a menial office job (where she steals stationery) and has the odd tumble with her married neighbour.

He's a crumpled college professor pre-occupied with finishing an obscure reference book and dedicated to dodging commitment to his long-suffering Polish girlfriend.

When dad (Bosco) begins to go doolally in the strange geriatric otherworld that is Sun City, Wendy and Jon are summoned from their insular lives on the East Coast.

Jenkins is particularly strong on this surreal parallel universe of infirmity where the sun always shines, pastels dominate and the favoured mode of transport is a golf buggy.

From the blue skies of Arizona, Jon arranges for his barely functioning father to be taken to a grim institution seemingly crushed by leaden skies.

Any grim foreboding about the depressing subject matter is almost immediately extinguished by the warm-hearted chemistry between Linney and Hoffman.

The only thing Wendy and Jon have in common is their overbearing dad and now they are forced into a situation where they really have to get to know each other.

It is this tentative bonding that gives the film its restrained optimism and gives the two stars ample opportunity to explore their damaged characters.

The pleasures are small but intense and the spell cast in one of the most surprisingly moving films of the year is captivating.

Tim Evans