凌晨光（刘文治 饰）有一段悲惨的童年，长大之后，凌晨光遭到了国民党的迫害，所幸得到了名为绿娘（黄梅莹 饰）的女子的帮助。就在两人渐渐碰撞出爱情的火花之际，凌晨光遭到特务追捕无奈潜逃出国。一晃眼多年过去，凌晨光在国外名利双收，并且同绿娘重逢，两人携手步入了婚礼的殿堂。

1949年建国之后，为了报效祖国，凌晨光决定携家带口返回国内，哪知道刚刚回国没多久，就发生了文化大革命。凌晨光被扣上了反动派的帽子，一家人都遭到了非人的待遇。可即便如此，当凌晨光的女儿想要跟着男友离开祖国时，凌晨光还是反对了她的决定。

With the birth of New China, a husband-and-wife pair of Overseas Chinese painters resolve to return to the embrace of their motherland, and their child is born under the five-starred red flag. But these Overseas Chinese patriots are persecuted in various political campaigns and their daughter subject to discrimination from childhood. The male lead freezes to death as a fugitive and draws a giant question mark in the snow before dying. The daughter emigrates following the Cultural Revolution; when her relatives try to stop her, she says: "You love the motherland, but does the motherland love you?" Based on a script by Bai Hua, SUN AND MAN was completed in 1981 but permanently shelved following high-level criticism and a public campaign against its "anti-Party" character. The film is said to survive in the studio archive but has never been publicly screened. A Taiwanese adaptation of the script (with some modifications) was released in 1982 under the English title PORTRAIT OF A FANATIC.