Undercurrents surge in the imperial court of Great Jing. Everyone knows that Prince Jing is frail, idle, and has no intention of vying for the succession. The legitimate daughter of the Su family, a prestigious merchant family in the capital, is seemingly just an ordinary businesswoman proficient in the abacus and knowing only commerce. With a single marriage contract, the two people of disparate statuses are forced to marry, guarding against each other and feigning compliance. Yet after marriage, through layer upon layer of probing, the two successively break through each other's hidden disguises. Prince Jing, who appears sickly, is actually a chess player in the court who holds dark guards and has deployed strategies for years; the merchant's legitimate daughter, who seemingly only loves silver, controls a commercial intelligence network spanning across the country under her name. Each harboring secrets, they transform from a contract couple suspicious of each other into each other's only ally. Together, they join hands to clear away the maze of the court.