Moving house is always an adventure but Abby and Chris get more than they bargained for when their parents take them to their new home. The garden, with its playhouse and old tree, promises them hours of fun but soon strange events turn fun into danger...

Who are the two spooky old women from down the road and why are they so keen to befriend the children? Where have the cat and dog come from that nobody but Abby and Chris can see? Is their garden with its gnarled old tree an innocent space in which to spend long, summer days - or does it conceal something darker?

When the children's mother disappears, the children are forced to confront an ancient evil. Can they defeat the Fairy King through a series of dangerous challenges - or will he destroy them before they can rescue their mother and escape?