Backflow Teahouse: I Sold the Future in the Southern Song Dynasty

In the late Southern Song Dynasty, an apprentice in a small teahouse in Lin'an City accidentally discovered that when tea was poured back into the pot, time would go back three minutes. He tried to use this ability to eavesdrop on guests' conversations and predict danger, until one day, a mysterious guest pushed a half-cup of tea in front of him: "Where did you get this cup of 'yesterday's tea'?"