Book 38 of the Mandie Books.
After a vacation with Senator Morton in Florida, Mandie and her friends return to her home in Franklin, North Carolina, to learn that a large crack has developed in the secret tunnel beneath her house. The house could be in danger of collapsing. As the crack widens, Mandie finds a mysterious cavern behind it. What secret to the hidden past does the cavern hold? What she finally discovers is so scary it gives Mandie nightmares - and then she remembers her favorite Scripture.
More than six million Mandie Books have been sold.