When Andrew and his sister, Polly, arrive in Devon they are soon to realise that this is not going to be a normal holiday. The appearance and disappearance of the ghost of a strange teenage boy leads Andrew to discover a secret hidden in the garden of his aunt's old house.
As the story continues, he learns more about his rich ancestor and the disappearance of the family jewels, but will he ever find them? Nobody in the family believes him when he tells them of the strange boy that he has met in the garden and his aunt insists he is mistaken when he talks of the lane behind the high hedge. Read on to see if he can overcome his fears and find the jewels before his holiday is over.