Glasgow, Scotland, 1981. The McLachlan family have dominated the criminal underworld for more than a decade. Masters in extortion, murder and heroin trafficking, they hold the city in their iron fist.

But a war is coming to Glasgow; a war unlike anything the McLachlans have known before. Over the course of one night, they will discover the wrath of one man: Jack "Gorilla" Grant, former spy and now freelance assassin.

And he plays by his own set of violent, unforgiving rules.