When the Welsh poet Dylan Thomas and his flirtatious wife Caitlin sweep into war-torn London, the last thing they expect is to bump into Dylan's childhood sweetheart Vera. Despite her joy at seeing Dylan after so many years, Vera is swept off her feet by a dashing officer, William Killick, and finds herself torn between the open adoration of her new found beau and the wily charms of the exotic Welshman.

A teenager finds her perfect life upended when she's stalked by a mysterious doppelganger who has her eyes set on assuming her identity.

Patagonia narrates the journeys of two women - one looking for her past, the other for her future. The film inter-cuts between their stories, in which one of them travels south to north through the Welsh springtime and the other east to west through the Argentine autumn.