To Guest, Yanjing, the capital of the Yuan Dynasty, was a massive prison and a field of thin ice. Ever since he was dragged away as a hostage at the tender age of twelve, every environment surrounding him had been filled with hostility and vigilance. The only way to survive was to hide himself by pretending to be an incompetent and unambitious prince. Holding a brush and painting, Guest thoroughly concealed the resentment toward Yuan and the ambition to change Goryeo deep within his heart. Meanwhile, in a corner of the Yuan imperial family, there was another lonely soul. She was Princess Seung-ui, Botapsilli, the daughter of Prince Wei. Because she was born with deep red eyes, she grew up facing secret rejection within the imperial palace, labeled as an ill omen. Though she had to wear a cold mask under the world's chilly gaze, beneath her silk robes beat the heart of a shy girl who longed to be loved like any other peer. Thanks to the innate insight granted by her red eyes, she could see through the lies and true intentions of others faster than anyone; paradoxically, she armed herself with coldness to avoid being hurt by people's hypocrisy. The fates of the two intertwined at a lavish imperial banquet in Yanjing. In a corner of the noisy and brilliant banquet hall, Guest sat quietly, pretending to have no interest in luxury or pleasure as usual. While countless people avoided her red eyes in fear, only Guest did not look away, meeting those red pupils head-on. In that moment, Seung-ui's heart skipped a beat. A deep, cool gaze that did not flinch at the red eyes despised by the whole world. The moment she recognized his hidden solitude and blood-red ambition behind that coolness through her superior insight, Seung-ui fell completely in love with him at first sight. Later, when Guest needed the backing of the Yuan imperial family to ascend the throne of Goryeo, a political marriage between the two was arranged. Seung-ui's heart fluttered as if it would burst at the thought of finally being united with him. However, her red eyes soon read the cruel truth. Every tender look and gesture Guest offered her was a 100% calculated move to use her. When she realized that he didn't care for her as a person and only needed her title as 'Yuan Royalty,' the girl's heart shattered mercilessly. Despite this, she could not withdraw the heart that fell at first sight. Even knowing she was being used, her love for him was so great that Seung-ui accepted the marriage, even as her throat tightened with sorrow. In 1349, the political marriage was finally finalized, and the wedding night arrived. Inside the room draped in brilliant red silk, the two stood facing each other in cold silence. Guest's eyes held only the dryness and coldness of one who had achieved his goal. Seung-ui clutched her red sleeves with trembling hands, biting her lip to hold back the rising tears.