Ten years after the events of Diary of a Serial Killer II: Ice Man, the infamous serial killer/hitman dubbed as the Ice Man by law enforcement and the media has relocated to New York City with his family after being pursued by a relentless police detective in Massachusetts. Continuing his profession as an elite hitman for the Mob in NYC, the Ice Man is honing his lethal skills as he builds his reputation as NYC's deadliest hitman.However, the Ice Man is not the only killer in NYC. A vicious, sexually-motivated serial killer known as the NYC Ripper is murdering New York City's most beautiful co-eds one borough at a time. As the body-count rises, NYPD Detectives have called in FBI profiler, Steve McClure, to assist in the investigation. Ten years ago, McClure was the lone survivor of the infamous Frat House Massacre perpetrated by the Ice Man at Farmington State University after the Ice Man discovered that the frat president and several other frat members were going to be acquitted for the violent rape of a freshman student. Now McClure is on the trail of the NYC Ripper - unaware that the vigilante who slaughtered everyone in his fraternity is also operating NYC.When the NYC Ripper kidnaps the Ice Man's beautiful eighteen-year-old daughter Rachel, it becomes a race pitting the NYPD and FBI against the Ice Man to determine who will track down the Ripper first. With time running out for the Ice Man's daughter, will the FBI or the Ice Man be able to find her before she is violently tortured and killed by the NYC Ripper?