Love is a strength despite the pain. Shanghai, 1940s: during Sino-Japanese war. By day, Lee De-Chang serves as the general manager at Bayer Pharmaceuticals, and at night he operates a secret gun-part factory. In public, he is engaged to Lily, the daughter of a wealthy businessman from Hong Kong. In private, he longs for Mei, his beautiful housekeeper from Suzhou, who works to repay her husband's debt. His German stepmother, Elke, meets Lily and tries to hide her impressions of her; after all, she wants her stepson to be happy. She sees Mei around Lee's house and likes her but realizes that she is already married. Mei feels guilty that she lives in the comfort zone in the posh French concession while her husband fights in the battles. She uses her spare time to improve herself but inadvertently forms a relationship that haunts her for many years. Unpredictable Winds is a story of unrequited love, secrets, desire, and an unintended friendship that leads to devastating consequences.