Another gripping page-turner from historical murder mystery author C.S. Harris. WHAT CANNOT BE SAID is book 19 in the series which follows the marvelous Sebastian St. Cyr, a nobleman and retired Napoleonic war military officer who investigates murders. Sebastian is such a compelling character. He’s smart and gutsy, and utterly fierce in his pursuit of the truth, even when it puts him and his compatriots in harm's way. This is one of my favorite series, and I eagerly await each year’s new release in the spring. As usual, I gobbled this whodunit up greedily as soon as I got my hands on it and emerged at the other end delighted in the story and sorry for the inevitable conclusion.     Each book can be read as a standalone, but readers will be best rewarded by reading in order, to understand the rich complexities of the myriad relationships between Sebastian and others. The well-rounded secondary characters bring great depth to the stories and enrich the reader’s enjoyment. I especially adore Hero, Sebastian’s wife, and noblewoman, who is a crusader for justice in her own right and a ferocious defender of Regency England’s many downtrodden.     Harris does a bang-up job in her settings. Regency England is lavishly evoked in her writing, and one can almost smell the fetid Thames or hear the costermonger’s cry while reading. The mystery is brutally compelling, and I love how many savage individuals are in the running for the many deaths in WHAT CANNOT BE SAID. I was surprised by the perpetrator, and that’s always so fun to have that lightbulb moment in a murder mystery! There are plenty of satisfying twists that made me grin ear to ear.