The "one thing" is happiness. In a mosaic of inter-connected and mostly secular stories, we watch a group of strangers in their quest for happiness and their responses to what fate dishes up.

A tightly woven script is complemented by a fine ensemble cast which includes John Turturro as a physics prof struggling to find a formula for self-fulfilment, Matthew McConaughey as a cock-sure lawyer who thinks he's got it all and a gripping performance by Alan Arkin as Gene, an insurance-claims adjuster who can't understand why one of his staff has so much to smile about when his own life is such a miserable mess.

The film's strength is that it eschews glib, feel-good answers. It reminds us of the fickleness of fortune and how the kindness of strangers can save lives.