After the brutal rape and murder of his 16-year-old daughter, widowed father Sang-hyeon stumbles into an ever-widening conspiracy of rage, revenge and murder. With the help of a mystery caller, Sang-hyeon is led to an address where he finds the electronic evidence of the crime against his daughter - and gets a chance for vengeance from one of the perpetrators. With the police on his heels, Sang-hyeon heads off to find the second rapist in this timely exploration of justice in the digital era.