After Sophie sees the ghostly face in the church window next to their private school, she and her friends Margaret and Rebecca are quickly swept up in a mystery involving an eccentric old lady who has found a mysterious birthday card addressed to her estranged daughter containing the first of several clues in an elaborate scavenger hunt. With the help of some good friends and a pretty cool teacher, the girls work together to solve puzzles involving everything from religion to literature (and even math!), in the hopes of finding the treasure at the end before several other suspicious characters get their hands on it first. But will it be enough to bring a broken family together again? And can the girls do it without getting expelled—or even arrested?
