Twenty years later, Mark Renton (Ewan McGregor) returns to Edinburgh, Scotland and the life he left behind. Feeling nostalgic after starting a life in Amsterdam, Mark explores the old haunts looking for people he once knew. Spud (Ewen Bremner) has had difficulty becoming accustomed to a normal life where things Daylight Savings has made him an hour late to all sorts of engagement from work to child visits. Still a junkie, Spud tries to kill himself just as Mark is knocking on his door and finds him in time to save his life. Simon aka Sick Boy (Jonny Lee Miller) lives the life of a criminal blackmailing school teacher and running a bar he inherited. In prison, Begbie (Robert Carlyle) plots escape and targets his rage towards revenge.
All of Mark's friends hate him for what he did at the end of the first film. Simon only pretends to forgive him in order to use him to help open a brothel to keep his prostitute girlfriend Veronika (Anjela Nedyalkova). Inspired by Mark, Spud starts to write everything down and helps with the remodel of the bar with his construction experience. Begbie breaks out of the hospital where he was being treated and returns to his wife and kid. He reenters a life of crime, burglarizing homes with the house of his son and selling them to their old drug dealer.
Mark and Simon pick up old crooked habits including robbing a bar full of Protestants after singing an impromptu song to escape being caught. Simon tells Begbie to lay low hiding the fact that Mark has returned so as to continue using him. The two former junkies apply for an EU small business to receive funding for their brothel but other gangsters in Edinburgh don't look kindly on the competition. The misadventures continue as Mark must go to Diane (Kelly Macdonald), now a lawyer, to help Simon avoid jail time for his blackmailing schemes. Mark also strikes up a relationship with Veronika behind Simon's back.
Begbie turns into a villain as he runs into Mark at a bar and chases after him trying to kill him. Begbie goes on the hunt discovering Spud's writing that is brutally honest even including the compensation he received from the stolen drug deal money back in the original. Tricking them all to the pub, there is a final confrontation from the old friends that comes to an emotional climax. The film does a could job feeding off the nostalgia of the old one but telling a great story as a continuation.
I have always been a bit disturbed by the first story of Trainspotting, from the tragic deaths due to drug addiction to the sordid life lived out by these individuals. I have found the humor in the awfulness of the situation and found this film equally funny and entertaining without so much of the disgustingness of the first one. The world has changed and these characters have gone on living lives to be expected of former junkies. They picked back up on the feeling of the first one and executed an effective revisit of a classic story.