The Hunt for the Seventh, by Christine Morton-Shaw...and I COULD NOT PUT IT DOWN!!! If you like mysteries, ghosts, suspense, and children's chapter books, then this is a must read!
It is about a family (a father, a son, and a daughter) who moves into Minerva Hall so that the father can be the full-time gardener. The son, Jim, comes across the ghosts of six Minerva children who have died every 30 years on the Summer Solstice. These ghosts urge him to find the seventh child, and they give him clues throughout the story. Will he find the seventh child in time? What will happen if he doesn't? Read the book to find out.