One London Day by Chris Humphreys

One city, one day, and a battle of wills reaches boiling point Joseph Severin, a respectable North London businessman, has a lucrative side job. He's doing the books, old school (because these days the only trail you can't trace is a paper one) for a rogue MI5 outfit, the Shadows, headed by psychopathic Sebastien. However, when the game is rumbled, Sebastien sends hitman Mr Phipps to kill Severin and get those books back. The spider web of collateral damage will be extensive, taking in Lottie, for whom Severin has developed a sudden, wild passion; Sonya, a Russian escort with a desperate deadline; and at MI5, the ambitious Ellerby, who has them all in her sights. It's the hottest summer in fifty years and in the shadows, a deadly domino effect is about to spill out into the harsh light of day.