Like all the St. Cyr mysteries, the greatest strengths in this book are the complex, poignantly developing relationships, intricately plotted and enhanced by fascinating, well-researched period detail. The avaricious manipulations of the wealthy are balanced by the daily courage of indigent children sweeping streets for pennies. The immoral machinations of the powerful contrast starkly with the quiet nobility of a young widow refusing charity. This plot involves the murderous intrigue at the highest (and lowest) levels of society, laced with both the sordid and the humane, that one expects of the series. However, What Darkness Brings most notably strains and nurtures the connections between those Devlin loves most deeply and those he fears. The plot and relationships (which in other hands might seem maudlin) are deftly tangled. Harris skillfully manages Devlin's distrust of his father and father-in-law, divided feelings for the two women in his life, and uncertainty regarding his vanished mother and possible brother. Throughout the series, he is driven by his aching need for truth as much for himself as for the unjustly accused. But, it is his deepening appreciation for his wife that is most engaging. While Hero has always been Devlin's equal in both intellect and courage, her character here is ever more nuanced, and she becomes wholly worthy of the reader's (and Devlin's) loyalty. I eagerly await the next book! One note to the publishers: the online version sometime cuts off mid-sentence. I found it necessary to experiment with the font to ensure I wasn't missing out. Rather distracting.