A perfect "traceless" kidnapping case left the police at a loss. The reclusive Lu Xun was asked for help by the victim's family. At the scene, he "saw" a childhood memory from thirty years ago left by the kidnapper. During the investigation, he discovered that the victim, the kidnapper, and his sacrificed father were actually connected by a dusty spice smuggling case, and that unique "ghost aroma" came from an ancient plant that was supposed to be extinct.
