I liked the idea for this case, but pretty much nothing else. The beginning of this book is full of *intense* fatshaming, both from the protagonist towards herself, and from everyone else in her life. That starts getting mentioned less frequently at some point, but never quite goes away.
Both the police and our archaeologist protagonist are incredibly incompetent. Honestly, they deserve the press treatment they get here. A surprisingly large part of the book deals with pretty much everyone cheating on their spouses, which is okay apparently, since everyone does it.
The ending is mostly very foreseeable, and feels a little looney-tunes, as four groups of people chase each other in circles on the marsh.
The one good part of the book are the many descriptions of the saltmarsh, which are beautifully bleak and atmospheric.