A missing sister, a decades old mystery and decades old secrets, plus a little romance all made for a story too tempting to pass up. Tracy has been haunted by her sister's disappearance for twenty years. She let her drive home alone from a shooting competition and she's never forgiven herself. Add in the fact that she's had questions about the investigation and the trial of the man who was convicted of killing her sister Sarah, despite the lack of a body, and she's been obsessed. That obsession led her to change careers from teaching to police work and wrecked her marriage. Now, her sister's body has been found and she's determined to re-open the investigation, no mater what. 
 Despite her obsession, Tracy comes across as a likable person. She has compassion and empathy, she works hard, has a sense of humor, loves animals, and is just trying to see that justice happens. But her investigation means old secrets are at risk and she just may cause more harm to the town she grew up in. 
 Dugoni splits the story between the present and the past. The first 40 chapters or so, I stopped counting, alternate between the past and the present. The advantage to this format was that a scene wouldn't be interrupted by Tracy having a flashback. The disadvantage was that the chapters were short and just as I was getting into a chapter and was drawn in, it would end. After the flashbacks ended, the pace smoothed out and it felt like a quick read. I was surprised when I looked at the percentage read and saw where I was it. At 400 pages, it took a while but the story passed quickly enough that it didn't seem like it. I was engaged in the story and curious about what had happened and what would happen. 
 Dugoni wrote a solid police procedural that had some twists and turns. I did guess most of them but it took me until about 3/4 of the way through the book to figure out the last couple and I didn't guess the ending. I wish that some of the secondary characters such as the police chief and Tracy's father had been better fleshed out. They play pivotal roles but I didn't feel as if I could understand the choices they made; intellectually, I did but not emotionally. The main characters, Tracy and Dan, were well done. They grew up together in the small town of Cedar Grove but lost touch over the years. Dugoni nicely portrayed the changes that happen over time and the differences in our perceptions when we're children and when we're adults. In addition to the mystery there's a budding romance between Tracy and Dan that's nicely done. 
 "My Sister's Grave" was a gripping story that kept me reading until the end. It treads familiar ground and doesn't offer anything new but if you want a well-done mystery with enjoyable characters, pick up "My Sister's Grave".