Barbara Erskine - A legsötétebb óra (2017)

The truth is often not read in the pages of history books...
In the summer of 1940, all eyes are on the southern skies of Great Britain: these are the fateful days of the Battle of Britain. However, Evie Lucas' attention is drawn to something completely different: the cheerful and good-natured young pilot, Tony Anderson. The girl is a promising artist with a bright future ahead of her, and prefers more than anything else to capture the facial features of her love in more and more passionate portraits.
Seventy years later, recently widowed art historian Lucy Standish is trying to get back on her feet, but to do so she must unravel the mystery surrounding one of the paintings in her house. As he tries to untangle the threads, the outlines of a story that has been kept secret from the whole world for a reason emerges. Lucy must soon realize that her life is in mortal danger, because there are those in both the present and the past who would stop the truth from coming to light at any cost.