In the Republic Era, Changsha flourished under the rule of the legendary Mystic Nine—a confederation of nine elite families commanding absolute authority across the region. When a cryptic train arrives at Changsha station in 1933, the gates' supreme leader Zhang Qishan, serving as the city's military commander, joins forces with Qi Tiezui to uncover the truth behind the arrival. Their investigation unveils a sinister mining operation lurking beyond the city's borders, exposing secrets that threaten to destabilize the delicate balance of power among the Nine Gates.