The story is about an aging cowboy and his nephew who transport 500 horses from Oregon to Wyoming to sell them to the British Army. Along the way, their simple horse drive is complicated when they rescue five Chinese girls from a slave trader, saving them from a life of prostitution and indentured servitude. Compelled to do the right thing, they take the girls with them as they continue their perilous trek across the frontier, followed by a vicious gang of killers sent by the whorehouse madam who originally paid for the girls.

Broken Trail weaves together two historical events: the British buying horses in the American West in the late 19th century and Chinese women being transported from the West Coast to the interior to serve as prostitutes.

Twenty-two year old Chinese-Canadian Jade Li comes from a traditional Chinese family, who try to put on the perfect public persona at all cost so as to "save face". One primary part of this persona is prosperity. Jade's father hopes that true financial prosperity will become reality through penny stocks. Because of its instability, Jade's parents don't understand or widely publicize Jade's aspirations to be an actress. Their main want for Jade is to date and marry a nice Chinese boy, a goal for which Jade's extended family also strives as they are always trying to introduce her to Chinese boys. They believe that *the* boy is Andrew, with who Jade even agrees to go out. But Jade, beyond wanting to be an actress, wishes her family had more western sensibilities. She is attracted to a slightly awkward but persistent Caucasian English graduate student named Mark. Jade has to figure out how to both please her family, who would not approve of her dating a Caucasian, and be true to herself.