At last! At last! I will have my revenge! Ditta wants to be a detective - and when her best friend Max tells her that his new bedroom is haunted she has her first mystery to solve.

But as the spirit starts to communicate through Max's computer, Ditta discovers they could all be in terrible danger.

With the help of the school ghost Hilly, Max and Ditta must unravel the truth quickly - before the spirit carries out his terrifying plan of revenge...Softly spooky, charmingly comic: Margaret Mahy's brand new novel for younger readers has elements of Casper the Friendly Ghost and will appeal to readers of Davd Almond and Michael Morpurgu.

As ever with Margaret writing, at the heart of the story is a deep sympathy and affection for the child's point of view - the characters are love able, their relationships and camaraderie sweet, and it is full of delightful comic touches, fizzy dialog and wry observations about family and friendship.