Based on real-life crimes that terrorized Hong Kong in the 1990s, Logan (Tony Leung Ka Fai) is the head of leading a notorious human trafficking gang, abducting the children of Hong Kong's elite. Police forces decide to send in Sky (Louis Koo), a Hong Kong undercover agent whose mission is to infiltrate and save the hostages, all while bringing the gang and their leader to justice in this action-packed thriller.