Paul Gauguin was one of the most intriguing artists of late 19th century France. A stockbroker who abandoned Paris for a bohemian life in Tahiti, perhaps his best known, and certainly his most valuable work, "When Will you Marry?" sold for $300m in 2015, making it the most expensive piece of his to ever sell. Could Gauguin's very first pencil sketch for this painting have turned up in a quiet suburb of Manchester? Just to raise the stakes even further, the team are on the trail of a second possible Gauguin: a still life depicting a bowl of oranges. A Cambridge-based architect has spent years trying to prove that an oil painting he inherited from a family friend is a genuine work that dates back to the crucial moment when Gauguin discovered the style which made him famous. The team have got a battle on their hands, because the authenticity of both works has been called into question by leading auction houses. The quest to find out the truth about the two pictures takes them to Bilbao, Britanny, Paris and the Imperial War Museum. As they delve into the story of a German art historian who fled the Nazis for a new life in England, they stumble across a forgery scandal that is only beginning to come to light.