Mark Renton is finally a success. He now makes significant money managing DJs, but the constant travel, airport lounges, soulless hotel rooms and broken relationships have left him dissatisfied with life. Then he runs into his old partner in crime, Frank Begbie, from whom he'd been hiding for years. But the psychotic Begbie appears to have reinvented himself as a celebrated artist in Los Angeles and doesn't seem interested in revenge. Meanwhile, back in Edinburgh, Sick Boy and Spud are intrigued to learn that their old friends are back in town and concoct a new scheme for them all. Which is when things start to go horribly wrong.

With the festive season almost upon him, Detective Sergeant Bruce Robertson is winding down at work and gearing up socially --- kicking off Christmas with a week of sex and drugs in Amsterdam. There are irritating flies in the ointment, though, including a missing wife, a nagging cocaine habit, a deterioration in his genital health, a string of demanding extra-marital affairs. The last thing he needs is a murder to solve. Still it will mean overtime, a chance to stitch up some colleagues and finally clinch the promotion he craves. But as Bruce spirals through the lower reaches of degradation and evil, he encounters opposition --- in the form of truth and ethical conscience --- from the most unexpected quarter of all: his anus.