Sergeant Tim Ryerson of the North West Mounted Police is commissioned to round up a gang that smuggles Chinese laborers across the border. While visiting his fiancée, Sylvia Sturgis, at her father's ranch, Tim becomes suspicious of ranch foreman Ferdinand Baird, who is the leader of the smugglers. One night, Tim catches Baird smuggling Chinese across the border to the U.S., but Baird escapes and flees to the Sturgis house where he abducts Sylvia. Tim pursues Baird to Vancouver's Chinatown, raids the smuggler's headquarters, and rescues Sylvia.