Deep Shelter

In this gritty, white-knuckle crime thriller, Detective Nick Belsey--introduced in the acclaimed The Hollow Man as a shrewd, street-smart cynic who is one of London's sharpest, but most unprincipled, investigators--is plunged into a perplexing mystery of secrets, danger, and suspense beneath the city's streets.
Trouble once again finds Nick Belsey when he takes a date to an abandoned bomb shelter buried beneath the heart of London. One minute the young woman is there, and the next, she's gone, mysteriously vanishing into the dark labyrinth of secret tunnels. A seasoned cop with a bad reputation, Nick knows that if he reports her disappearance, he'll be the prime suspect. Instead, he's going to find her. It's not just her life at stake--it's his, too.
Determined to discover who else is down in those forgotten tunnels, and how far this secret network of underground passages extends, he plunges head first into the investigation--and into a dangerous game of cat-and-mouse with a ruthless enemy who would rather let an innocent woman die than reveal old Cold War secrets hidden deep beneath the city's streets.
An edgy, subversive thriller with the superb characterization of classic Lawrence Block and the psychological acuity and suspense of Sophie Hannah, Deep Shelter is a compulsively readable mystery from a master of literary suspense.