Lois Fox, upon whose shoulder is branded a Chinese idiograph resembling the letters "A. Y.," is rescued from a gang of Chinese ruffians by Brice Ferris. His servant Ming, in attempting to steal from her finger a ring that bears a mysterious green seal, is killed, and soon afterward a stranger named Strang arrives, also in search of the girl. Despite Brice's efforts to protect her, Lois is abducted and taken to the headquarters of Lao Wing, the leader of a secret Chinese society known as the Tong.

"Branded for life...and she knew not why?"