The basic plot idea is quite simple but the excellent screenplay adds a couple of extra layers. To make it work however, and to avoid over sentimentality it needed a performance from someone with the class of Marion Cotillard and she delivers in spades.
Michelle Williams gets the wagon train through despite the hindrance of the character who had been kicked out of ZZ Top. The desert landscapes are beautifully photographed and the wardrobe and props department have done a good job.