Sarah and Robert's father died when they were small, and their mum has recently moved in with Martin. He is a divorced father of three - Lauren, Zoe and Jake - and these three are coming for a first weekend visit at the beginning of the story. The story is a mystery about a ghost that the children see in the summer house they have made into a den, but the tensions and problems associated with trying to make two families into one form a distinctive and realistic background. The ghost, a sensitive boy who is trying to make contact with the children for some important reason, is also a weekend visitor, and as the children find out more about him and why he is there, they become a more cohesive family unit. A well-written, full-length novel.