Washed up in a storm, a part of a human body leads Detective Inspector and "Sarge and " Downs and Detective Senior Sergeant Nat Johns of the Criminal Investigation Branch based in Cairns, Queensland down to Melbourne to investigate why a man had fled so far north only to be murdered and his body disposed of at sea. They discover a dysfunctional family that has a criminal background all too willing to cover-up what may have happened to their son and brother. With the aid of Victorian police, they attempt to find the murderer and uncover the conspiracy that surrounds it.