Jiang Wanyi, the true heiress, is abandoned by the Marquis's household at a ruined temple on a snowy night. By chance, she discovers a mysterious door leading to a modern convenience store. From then on, she travels between the ancient and modern worlds, turning modern snacks, daily necessities, skincare and cosmetics, and all kinds of novel goods into rare treasures from the celestial realm. In the Great Qian Dynasty, she rises to power, humiliates her fake heiress rival, and takes brutal revenge on the Marquis's household. Along the way, she befriends Xiao Jiuci, the heir of the Prince of Zhenbei. Starting with a business catering to noblewomen, she expands into supplying military provisions and eventually becomes an imperial merchant before the Emperor. With just one door and a brilliant mind, she transforms from an abandoned daughter who was bullied and mistreated into a top merchant whose business spans both ancient and modern worlds.