"OUR MOST TALENTED HISTORICAL MYSTERY WRITER TODAY." —ANDREW GULLI, STRAND MAGAZINE

"THE GAME IS MOST DEFINITELY AFOOT." —MICK HERRON

In 1910 London, Captain Vernon Kell's fledgling secret intelligence service faces being shut down before it has even begun its job of saving the British Empire from German and Russian spies.
Harassed by politicians like the ambitious Winston Churchill, bullied by Special Branch, undermined by his colleague's ill-advised foreign ventures, and alarmed at his wife's involvement with militant suffragettes, Kell is making no progress in tracking high-profile leaks from the government. To make matters worse, his best (and only) agent, Wiggins, would rather be working cases of his own.
Wiggins grew up on the streets of London, one of the urchins trained in surveillance by Sherlock Holmes and known as the Baker Street Irregulars. He has promised to avenge the death of his best friend, and to track down a missing girl from the East End.
But when his search takes him to an embassy in Belgravia—an embassy that's actually a high-class brothel presided over by the fearsome "Big T," one of his fellow Irregulars—Wiggins is drawn into a conspiracy that will test both his personal and professional resolve.