Desperate for glory and respect, Major Percy Fawcett (Hunnam) accepts the Royal Geographical Society's offer to draw up maps dividing Bolivia and Brazil. However, on this 1906 expedition to South America Fawcett is distracted by the discovery of a culture that predates Western civilisation, a claim ridiculed upon his return to London. Convincing the well-to-do that he’s on to something, Fawcett returns to South America with friend Costin (Pattinson) to explore his theory of a lost city he has dubbed Z…

Like last year's Embrace of the Serpent, this based-on-a-true-story biopic has its roots in Conrad (and perhaps the bizarre discovery of an opera in the middle of the dense jungle a nod to Coppola's Vietnam re-imagining) but this is no rehash and nor is it a by-the-numbers adventure story. In adapting David Grann's best-seller, writer-director James Gray (We Own The Night) plays with convention: splitting the expedition over three attempts (the last being with Fawcett's son Jack (Tom Holland)) could have lessened the impact of being lost in the jungle and the ominous atmosphere Gray has instilled but the sojourns back home, and the episode where Fawcett commands a company in the trenches at the Somme, are never a distraction from the story’s ultimate goal. That's down to another off beam tactic that Gray employs: he ensures his adventure story is an introspective character-driven one, which don't come along often.

Gray veers from exposition-heavy moments to others that are beautifully understated: there are only two small scenes that explain Fawcett's obsession with finding the lost city: he reflects that he will be the only soldier of his rank at a soiree without medals on his jacket, and a passing comment by a superior (Ian McDiarmid) that the mission will help restore his family name. It's enough to get the audience behind Fawcett's drive and perhaps excuse his tendency to abandon wife Nina (Sienna Miller) and his family.

Hunnam is a commanding presence in the lead while Pattinson is deliberately unshowy in a supporting role. Despite the story side-lining her character Miller is terrific, making the most of what she has, she's there to highlight the hypocrisy of her husband: his progressive thinking that there were more advanced races than those of his close-minded peers, he outright rejects her appeal to join him in the Amazon, stating that a wife's role was at home raising children. Frustratingly, after toying with this facet of his character Gray balks at exploring it further. What could have been given more oomph too is the rape of the natives by rubber barons and slave traders.