A newly married French military officer leaves the army and heads off on a dangerous journey to Japan in the employ of an entrepreneur who has commissioned him to bring back valuable silkworm eggs. During his stay, he becomes besotted with the mysterious concubine of a local baron, and on his return home the obsession threatens to destroy his marriage. Period drama based on the novel by Alessandro Baricco, with Michael Pitt, Keira Knightley and Sei Ashina.

French silkworm trader Hervé is married to the beautiful Hélène. When an outbreak of disease ravages European silkworms, Hervé must travel to Japan to retrieve healthy eggs. After a long journey, Hervé finally arrives at a village where he can buy them. He becomes infatuated with a young concubine and goes to great lengths to see her again. But, when war breaks out in Japan, the concubine flees, forcing Hervé to return home to his wife.