It's DS Logan McRae's first day back on the job after a year off on the sick, and it couldn't get much worse. Four-year-old David Reid's body is discovered in a ditch - strangled, mutilated and a long time dead. There's a killer stalking the Granite City and the local media are baying for blood. If that wasn't enough, Logan also has to contend with a new boss, DI Insch, who doesn't suffer fools gladly and thinks everyone's a fool.

From the outside, Glenfarach looks like a quaint, sleepy village, nestled in the heart of Cairngorms National Park, but things aren't what they seem. The place is thick with security cameras, and there's a strict nine o'clock curfew, because Glenfarach is the last safe haven for people who've served their sentences but can't be safely released into the general population. For Detective Constable Edward Reekie, this was supposed to be a simple delivery job—drive his new boss up to HMP Grampian and collect Marky Bishop, take him to Glenfarach, then head back home again.

Former soldier. Ex-copper. Current man on the edge. Shunned by his old colleagues, and dividing his time between a dead-end job and the bottom of a whisky bottle, former Police Scotland detective superintendent Bob Hoon’s life is a mess. Then an old face from Hoon’s Special Forces days turns up asking for help: His teenage daughter has been missing for months, the police have drawn a blank, and he needs the kind of help that only Hoon can provide. And besides, Hoon owes him one.

Welcome to the Misfit Mob... It's where Police Scotland dumps the officers it can't get rid of but wants to: the outcasts, the troublemakers, the compromised. Officers like DC Callum MacGregor, lumbered with all the boring go-nowhere cases. So when an ancient mummy turns up at the Oldcastle tip, it's his job to find out which museum it's been stolen from. But then Callum uncovers links between his ancient corpse and three missing young men, and life starts to get a lot more interesting.

Detective Constable Angus MacVicar has just landed his dream job – transferred out of uniform and assigned to Oldcastle’s biggest ongoing murder investigation: Operation Telegram, hunting the “Fortnight Killer”. Every two weeks another couple is targeted. One victim is left at the scene, their corpse used as a twisted message board. The second body is never seen again. This should be the perfect chance for Angus to prove himself, but instead of working on the investigation’s front line, he’s lumbered with the forensic psychologist from hell.