Even more of a historical stretch: the ongoing spy saga of Maggie Hope, the "secretary" who happens to have a mother who is an uber-Nazi strategist, a father who is a Bletchley genius, and a sister somewhere on the Continent in the Resistance. In the latest installment, PM Churchill lends her to Eleanor Roosevelt during a state visit. Mrs R, in turn, enlists her help in trying to overturn a capital punishment sentence for an African-American teenager framed for murder. The plot of each book in the series is so unbelievable (and the writing so breezy) that I think they'd make better sense in comic form -- a la Prince Valiant. And yet I can't stop reading. It's complete escapism -- modern social attitudes and barely-masked modern issues, wrapped in the quasi-nostalgic era of the "Good War".
In the opposite vein, I can't stop reading the Maisie Dobbs series for its utter melancholy. It takes the main character ten books and twenty years to finally get to a place where she can move beyond her personal trauma from WWI to find some happiness (which get snatched cruelly from her in Book 11); unfortunately, it happens on the brink of WWII so the readers watch as another war and trauma lurk in the future. The latest book has Maisie going on a mission to Munich to free a businessman important to Britain's war preparation effort. She solves a murder in the course of her duties, of course. And even though at the end of the story, she starts the process of setting up her old detective agency, it seems hardly likely that the next book will have her relegated to the sidelines of the coming conflict.
Or maybe I'm just bitter that The Bletchley Circle ended after only two seasons and Land Girls after only three.