The Crime Trade book by Simon Kernick

When Operation Surgical Strike goes horribly wrong, suspicion quickly falls on one of the officers involved: Stegs Jenner. No ordinary undercover cop, Stegs is a man who's always lived life on the edge. Now he decides to go it alone. DI John Gallan and his partner DS Tina Boyd are part of the subsequent investigation that will take them to the heart of one of London's most notorious criminal gangs. What they cannot know is that they've also embarked on a collision path that will lead one of them straight into the rifle sights of the enemy. Published By Random House on 2005