Porno is the sequel to Trainspotting, the highly acclaimed book(and movie) about a group of drug-addicted schemers in Edinburgh, Scotland. It rejoins the group ten years after the conclusion of Trainspotting and it is quickly clear that while the time has changed everyone, some things never change. While heroin use dominated Trainspotting, cocaine use seems to be the new drug of choice. As before, money is the prime motivator and everyone has different means toward this end.

The main scheme this time involves Sick Boy's idea to produce a pornographic film. There are twists and turns in the plot that involve other schemes and manipulations of course, and Welsh does a good job of writing each character's actions based on their own self-interest. The interplay of the goals and desires of each character is cleverly written, with each chapter written from the first person perspective of whichever character the chapter focuses on.

There are new characters brought in and all the old personalities are back. A constant theme is that everyone looks out for themselves first, while trying to balance loyalties and circumstance in order to get the biggest cut from the action. Begbie is back and serves to create tension with his predictably unpredictable rage and violence. Sick Boy is the same egotistic manipulator who conceives of the idea and plays the role of mastermind. Renton is back from Amsterdam, where he fled with the loot at the conclusion of Trainspotting and is a much more subtle manipulator. The lovable Spud is pitiful and mostly well-meaning if a bit vulnerable to the guile of his friends and his addictions. The beautiful Nikki enters as the star of the film, along with Terry the bar owner, both of whom are looking to have fun while scoring easy money. Other minor characters are woven in and affect the plot here and there which adds to the complexity of the story.

Each character remains true to their personality, with good and bad results. Everyone has specific desires and fears that are at the root of their actions, but these are not always apparent to everyone else. A common idea amongst them is that they are aging, and something must be done soon with their youth before it slips away completely. It is interesting to note that some of the diverse behavior of the individuals boil down to the exact same anxieties. There is a good study of human nature here, with two distinct levels: how we think and feel about things, and how we act on those thoughts and feelings in a group. The interplay of both serves the development well.