Slaves of Obsession 
Hester Monk emerges as a fascinating character in her own right. Her relationship with the enigmatic William, whose fragmented recollections (of who and what he was before the accident that erased most of his memory) still haunt him, is thoughtfully evoked. As usual, Perry handles the secondary characters with brio. Breeland, in particular, becomes in the author's capable hands a man whose obsessive devotion to the Union cause underscores his inability to return Merrit's love. As Hester tells the infatuated young woman, "To see the mass and lose the individual is not nobility. You are confusing emotional cowardice with honour.... To follow your duty when the cost in friendship is high, or even the cost in love, is a greater vision, of course. But to retreat from personal involvement, from gentleness and the giving of yourself, and choose instead the heroics of a general cause, no matter how fine, is cowardice." This sixth entry in the Monk series evokes the era in which it is set with a fine eye for details of dress, manners, décor, and culture, while skillfully unfolding the emotional and intellectual depths of both William and Hester, whose well-honed intelligence makes it clear that she, too, deserves a series of her own. --Jane Adams
Reviews
William Monk is one of Perry's regular characters. Set in Victorian England there is a cast of characters with passionate beliefs and different motivations. I suspected one to be the evil antagonist--but discovered it was not him as the story progressed. (All the clues are not available within an abridgment.)
There were a few interesting twists...and the break from the underwater sequence with Monk kept me on edge.
In the book you embark on a voyage to America coinciding with the beginning of the American Civil War. Hester and William Monk travel by boat on a mission to bring back the run-away daughter of Albertson. Meritt's confused passion for the abolishment of slavery is exhibited as a romantic crush for Lyman...a Northerner bent on purchasing guns from her father-- despite Albertson's continued refusal to sell them to him. Albertson's murder just happens to concide with the gun delivery to Lyman.
The return to England takes you through the trial and the revelation of what actually happens after both Lyman and Meritt are acquitted of wrong doing.
This engaging work will put Anne Perry on my list of authors to explore further.
I, too, could not finish the book and stopped short of the trial in London. It opened fairly well with the moral issue of slavery becoming a heated topic at a London merchant's dinner table. The 16-year old daughter is indignant that her father is selling efficiently lethal rifles and ammunition to the Confederacy. Her passion has been influenced by a rival Union arms buyer who pleads the moral case as well, and with whom she later flees to the U.S.
I found the characters convincing one moment, and then rather wooden the next. The same with the Victorian milieu -- it struck me as unevenly depicted. For me this was a major flaw as the best historical novels and detective stories have an optimal weaving of story, character and environment to make the "whole cloth", so to speak.
In addition, the detective Monk seemed a rather lame chap in this work. Mystery detectives, even when they're not doing much or are hovering in the background, ought to have a looming presence as they are to a greater or lesser degree the moral presence in the story, the one who must discover the truth. The Adam Dalgliesh character of P.D. James is almost always successfully rendered in this way, even though he may be absent for a good part of the story.
What went wrong with SoO? Look at the author's extensive credits at the front of the book. Ms. Perry is a "writing machine" if there ever was one, and prolific genre writers can get overextended, disconnected and thin from time to time. That's what happened here, I wager.