London is burning under the Blitz, but MI6 agent Katrin Nissen knows the gravest danger isn't falling from the skies-it's coming from inside Britain's own intelligence ranks. 

A covert Nazi faction has infiltrated British intelligence in a plot to overthrow the government and install a German-controlled puppet monarchy-toppling Britain from within without firing another shot.

Framed for a colleague's murder, Katrin is forced underground, hunted by the very service she swore to serve. Together with her husband, MI6 operative John Breckenridge, and a disgraced former agent with a past as dark as the city's blackout nights, she searches for the mastermind behind the deadly plot.

Then the unthinkable happens-Princesses Elizabeth and Margaret are kidnapped, and King George VI and Prime Minister Winston Churchill are marked for assassination. The conspiracy is no longer theory-it's minutes from success. When a trusted colleague hints the answers Katrin seeks may lie in occupied Denmark, she escapes London. Returning to her homeland and her family, she rejoins the Resistance, freedom's last hope. But will it be in time?