Slough House 4: Spook Street - Mick Herron

Now, far from joining the myths and legends of Spook Street, River Cartwright is part of Jackson Lamb's team of pen-pushing no-hopers at Slough House. Which doesn't mean he won't ditch everything and go rogue when his grandfather comes under threat. Lamb worked with Cartwright back in the day, and knows better than most that this is no innocent old man.