Barney Thomson — awkward, diffident, Glasgow barber — lives a life of desperate mediocrity. Shunned at work and at home, unable to break out of a twenty-year rut, each dull day blends seamlessly into the next.

However, there is no life so tedious that it cannot be spiced up by inadvertent murder, a deranged psychopath, and a freezer full of neatly packaged meat.