In 1926 in Shanghai, there are two gangs competing for territory and resources: the Scarlet Gang, run by a native Chinese family the Cais, and the White Flowers, a Russian gang led by the Montagov family. These two gangs have frequent street fights over territory.

One night on the river boardwalk, two members of the Scarlet Gang encounter two members of the White Flowers. They are ready to shoot one another when a British policeman intervenes. Just as he is warning them not to fight, a monster from the river attacks them all. One man escapes, and the remaining men, who are infected by the monster, tear, out their own throats with their nails and die. 

Nineteen-year-old Juliette Cai, the daughter of the Scarlet Gang’s leader, comes back to Shanghai after living in New York for four years to help her father conduct business. Juliette meets a British trader, Walter Dexter, at a burlesque club where her cousins Rosalind and Kathleen work—Rosalind as a dancer, and Kathleen as a server.

Walter chats with Juliette about her education in New York and mentions that he has a son who is Juliette’s age.