Bruce Robertson is a corrupt, manipulative detective sergeant with the Edinburgh Police Department, teetering on the brink of mental collapse. His life is a whirlwind of drugs, alcohol, and debauchery as he manipulates everyone in his path to secure a coveted promotion to detective inspector. Bruce's scheming is fueled by his ambition and a desperate need to assert control, not just over his colleagues, who are all vying for the same promotion, but over every interaction he encounters. He engages in a series of underhanded tactics to undermine his rivals and is willing to exploit his friends' weaknesses for his own gain. His only semblance of humanity seems to emerge through his distant relationship with his estranged wife and daughter, whose absence haunts him.

As his life spirals further out of control, Bruce's mental state deteriorates rapidly, exacerbated by his drug-induced hallucinations and his increasing cruelty toward others. He faces constant harassment by a mysterious caller who seems to know a great deal about his unsavory actions, adding to his paranoia. A secondary plot line involves a racially charged murder case that Bruce is assigned to solve, which only serves to increase the pressure he's facing. Despite his declining grip on reality, Bruce cunningly manipulates every turn of his investigation, leaving a wake of chaos and betrayal as his personal and professional lives begin to merge into a singular destructive force.