Group Fifteen Files (Michael Ridpath) Books in Order

Michael Ridpath's place in the Group Fifteen Files world comes through Little Sister, a compact spy thriller written inside Mark Dawson's larger covert-ops universe. It helps to know that Group Fifteen is a secret British outfit used for jobs that official agencies would rather not own, but you do not need a long reading list to get started. The novella is built to work fast and land hard.

The central figure is Bjorn Thorsson, a former SAS soldier trying to live a quieter life after too much violence. That hope disappears when his sister Gudrun gets into trouble with a wealthy hedge fund owner. Bjorn steps in because he has to, not because he wants a mission. That gives the story a personal charge from the opening pages. This is not a tale of patriotic duty or official chain of command. It is about a man who will do ugly things if that is what it takes to protect family.

Family comes first.

That matters because the real enemy is bigger than one dangerous financier. Group Fifteen itself looms over the book as the kind of hidden organization that can watch, manipulate, and remove problems without ever explaining why. In Little Sister, Bjorn runs into people who are backed by resources, tradecraft, and the cool certainty that ordinary lives can be treated as collateral damage. The suspense comes from watching one stubborn outsider push back against a system that assumes it always wins.

The settings help keep the novella sharp. The action begins in a modern world of money and influence, then shifts into terrain that feels rougher and more exposed, including the Scottish Highlands. Ridpath uses that change well. Closed rooms and financial power give way to open ground, pursuit, and the physical reality of trying to survive when there is nowhere safe to stop. Because the book is short, scenes tend to arrive already under pressure. There is very little drifting or setup for its own sake.

Ridpath also brings in elements that will feel familiar to readers of his own work: a bruised protagonist, a chilly atmosphere, and a strong sense that old damage still shapes present choices. Even in novella form, the story has room for grief, anger, and the awkward fact that doing the right thing can look very wrong from the outside.

So what should you expect overall? A lean, self-contained thriller that sits comfortably beside the wider Group Fifteen books while keeping its focus tight on Bjorn, Gudrun, and a collision between private loyalty and state secrecy. If you want a quick entry point into this shadowy spy world, Ridpath's installment is an easy one to pick up.