Messenger of Truth takes our psychologist/detective heroine into the world of art, where she is commissioned to determine whether an artist's tragic death was accidental or connected to any of the controversial scenes he painted.
Parts of An Incomplete Revenge reminded me of "The Lottery" - the book takes Maisie to Kent to uncover the thoroughly dark tale of what one small, xenophobic town does during the War in the aftermath of a Zeppelin raid, as well as in the subsequent ten years during annual hop-picking season when Gypsies and Londoners camp in fields to help with the harvest. (It also reminded me that I've been meaning to read a comprehensive history of the Roma for a long time now.)
In these two books, the main character starts to shed her wartime burdens - a rift with her mentor forces her to be more independent; her wartime love, brain-dead for a decade, finally passes away, so she can no longer carry a torch for him; she starts to have hobbies that bring brightness and color into her life. And readers get to see Britain change with Maisie: slowly, book by book, telephones and electricity reach more homes; cars replace horses and carriages; rigid class distinctions fade.
Of course, the tragedy is that readers know that another war is looming 8 years on the horizon.