Cold-Blooded Killers is about two hitmen who go to the Isle Of Arran to do a routine hit. Devlin and Conner have been contracted by a crime firm to find and kill one of their crime bosses "Fraser McCabe". McCabe fled with a lot of money to start a new legit life.
The crime firm get a tip off McCabe is on the Island, but they don't know where he is. They have sent hit teams in the past to find and kill him, but none of them came back alive. Devlin and Connor have three days to pull off this job, before McCabe finds out from locals that a new team is here to kill him. Devlin begins to understand why McCabe started a new life on the island. This throws a spanner in the works, after Devlin also gets seduced by the island life.