Xiao Yunjin, the Marquis of Zhenbei of Dajing, and Luo Haitang, the legitimate daughter of the Chancellor, fell in love at first sight on the Lantern Festival night, using half of a tiger tally as a token and pledging the promise of ten miles of red attire. To seize military power, the Chancellor and the third prince secretly colluded with the enemy and framed him, causing Xiao Yunjin to die in battle at the northern border. Suffering the loss of her beloved, Luo Haitang accidentally discovered that her biological father was actually the mastermind behind the scenes, and resolutely broke ties with her father. In the end, dressed in the self-stitched red bridal gown and holding Xiao Yunjin's memorial tablet in her arms, she committed suicide out of loyalty, fulfilling that unfulfilled promise of red attire in the most unyielding way.