This is the fourth book Wendy Mass has set in the small, unusual town of Willow Falls, and the title seems to imply it is the final book in the series.  As such, it does a really nice job of wrapping together the other books, and explaining the mysterious character that linked her other books.  While bringing satisfactory closure to this delightful series, it also manages to set up the possibility of a companion series to follow.  It brings back well-loved characters and ties together mystery and humor and time-travel as Amanda and Leo (the main characters from the first book in the series, 11 Birthdays) work together to unravel and rescue Grace, who has fallen into a strange trance.