Matty is devastated when she learns that her father and mother are going to work in Burundi, meaning that she must go to a boarding school instead of the local school with all her friends. Eventually, she settles into St Anne's, where she makes a special friend as well as an enemy. Her new friend is a Christian who helps her to see that Jesus can deal with her anger and bitterness. Together, the two girls have an adventure in the school garden, where they find an old tunnel and discover the secret it has held for hundreds of years!