Grave Secrets is the first book by Charlaine Harris that I have read that isn't in the Sookie Stackhouse series. I wasn't even aware that she HAD another series until I read this one in the Harper Connelly series. Apparently it is the 4th and final book of the series. Harper is able to stand on graves and know how the person died. She travels around the country with her step-brother/boyfriend (I know, kind of creepy but their parents are no longer married) and "reads" graves for people willing to pay for it. She developed this ability as a teenager after being struck by lightning.
In this book, Harper and Tolliver are trying to reconnect with their younger half-sisters who live in Texas with their aunt and uncle. Their mother is dead and their father is in prison, at least until he is parolled. He tries to reconnect with them as well, much to Harper's and Tolliver's dismay. He and Harper's mother were raging drug addicts who neglected the family. Harper and Tolliver are in Texas to read the graves of the Joyce family and discover some disturbing secrets about the family that someone doesn't want them to know. They also hope to find out what happened Cameron, Harper's sister who went missing 8 years earlier.
I liked this book a lot better than the others by Harris that I have read. It is deeper, darker, and richer as a whole than the lightweight Sookie Stackhouse books. It is also somewhat cleaner but not much. There was still enough language and sex to make it rated R.