The sixth in the Maisie Dobbs, Psychologist and Investigator, series picks up on Christmas Eve 1931. Winspear has done a nice job of developing her characters throughout the series, allowing them to grow and change according to circumstances. Although a few characters strain credulity, that can be forgiven because they serve the greater purpose of the plots. Maisie, our intrepid but no-longer-young girl detective has risen from poverty and domestic service, past service as a nurse in France, to become the head of her own two-person detective agency.
The motif running through the series is the ongoing post-traumatic disorders suffered by the major characters from their service in World War I. I admire Winspear greatly for focusing on this theme because it gets past the usual chronological stereotype that goes: WWI (All Quiet, Please! We're on the Western Front over Here), then everyone drinks and dances with wild abandon through the 20s (The Sun Also Rises, But I'm Too Hung Over to Notice), then suddenly the Great Depression looms and novels channel "The Grapes of Wrath" or screwball comedies that foreshadow the rise of fascism in Europe (the deliciously frothy "Miss Pettigrew Lives for a Day" comes to mind).
Winspear allows her characters to remain firmly stuck in the events that shaped their youth; much more realistic. The time frame between the Great War and the early 1930s is so short that the characters are still working out issues and we are painfully aware many of them will never succeed. A non-fiction examination of this topic can be found in "Shook Over Hell: Post-Traumatic Stress, Vietnam, and the Civil War," by Eric T. Dean, Jr. Harvard University Press, 1997. Although I do not agree with all of Dean's hypotheses (the closer he gets to the present, the more his political views seem to ooze into his scholarship), he provides much valuable data and a fascinating look at an issue that gets regularly renamed (shell shock, battle fatigue, PTSD) but never goes away.
"Among the Mad" finds Maisie, Scotland Yard, and British Intelligence working, sometimes at cross-purposes, to find a killer bent on acts of mass violence against the civilian population of London. Moving from hand grenades to poison gas, the villain is suitably invisible and one step ahead to keep the plot moving. Winspear leaves us enough clues along the way that we can guess the ending if we wish, but most of her fans are just along for the ride to enjoy a good yarn, clearly told, and have a chance to revisit characters that have become old friends.
The Maisie Dobbs books are not high literature, but that may be a point in their favor with readers who are grateful for a good British lady-detective story with enough set dressing to create a sense of time, enough geography to create a sense of place, and enough historic detail to provide a painless "historic-novel history lesson," so that we feel less guilty for sitting down with a good read instead of doing something "productive" like the laundry. We'd much rather watch Maisie out-think, out-intuit, and out-resolve her Scotland Yard counterparts. (Has any independent detective character in a novel EVER said anything nice about Scotland Yard's effectiveness?) All this done while coping with the lingering pain and loss from the Great War and while transitioning into a world we, the reader, knows will be far scarier.