A wealthy young English gentleman, Louis Trevelyan, visits the fictional Mandarin Islands, a distant British possession, and becomes smitten with Emily Rowley, the eldest daughter of the governor, Sir Marmaduke Rowley. The Rowleys accompany Trevelyan to London, where he marries Emily. When the rest of the family goes home, Emily's sister Nora remains behind, under Trevelyan's protection. The marriage is initially a happy one and the couple has a baby boy. Then a seemingly minor matter undermines their marriage.