Judith Pella & Michael Phillips 
Shadows over Stonewycke (The Stonewycke Legacy Book #2) 

Shortly before World War II, Allison and Logan Macintyre’s marriage has fallen on hard times. When war breaks out, Logan gets involved in British espionage without Allison’s knowledge. While he goes to France to become an agent in the Underground, Allison faces the terror of The Blitz. Will they survive the tragedies of war? And is there any hope for their future?