"Detective K: Secret of the Lost Vampire" is a South Korean historical mystery film that follows the adventures of Detective K, a clever and resourceful investigator in the Joseon Dynasty. He is tasked with solving a series of mysterious murders that are rumored to be connected to a legendary vampire. As Detective K delves deeper into the case, he teams up with a beautiful woman who has her own secrets. Together, they uncover a plot involving royalty and dark forces, leading to thrilling encounters and unexpected twists. The film combines elements of comedy, action, and suspense, making it an engaging watch.