Four years ago, a veteran cop and an elderly gangster were killed in a gunshot attack. The only survivor and the dead gangster's protegee, the enigmatic and ruthless Tang Yi, is now the new gang leader, who will stop at nothing to find the murderer and plans an elaborate trap to lure him out of hiding. Honest police officer Meng Shao Fei is obsessed with knowing the truth behind this case, to avenge his mentor's death, and spends all his spare time tracking Tang Yi and trying to find what he is up to. When Meng and Tang Yi are kidnapped together and forced to survive in a cold mountain, things start to change between them.