A package addressed “For Su Tang” arrives at the forensic center. Inside is a report about her, signed by her sworn enemy, Lu Ze. Su Tang opens the first page and finds the words, “Cause of death: died of smiling.” She can’t help laughing. The report is riddled with errors, but every one of them points precisely to a code her father left behind before he disappeared. When Lu Ze storms in, furious and demanding answers, they discover that someone deliberately sent the report as a death notice. From clashing with each other to being forced to join forces, they investigate the mysterious figure behind the report, gradually uncovering a killer organization called “Smiles” behind a family massacre from twenty years ago, along with the inescapable fate binding their families together.
