Away from the frontlines of the Great War, British intelligence agents are fighting a battle of their own.

Newhaven, England. 1917.

Nurse Clara Dankworth learned long ago to go where her government ordered. Her newest assignment pairs her with fellow spy and doctor Thomas Lindsey to gather evidence on a prominent society figure suspected of being a German sympathiser. But when threats emerge from the shadows, Clara finds that in attempting to escape her past she hadn't run far enough.

Though one of MI5's top agents, Doctor Thomas Lindsey's maverick spirit often lands him in trouble with his superior. Clara's unexpected-and unwelcome-arrival as his newest assistant places Thomas's personal mission in jeopardy as his work of several years threatens to unravel. But in his determination to protect his secrets at any cost, he discovers Clara has more than a few secrets of her own.

When a notorious and elusive rogue agent casts a shade on Newhaven, Thomas and Clara are forced to trust each other in order to discover the answers they seek-both for England and for themselves. But with an enemy unknown and countless lives on the line, the lies they are living might be far safer than the truth that could ruin them all.