Professor David Ash is invited to Edbrook to calm the fears of the elderly nanny of the Mariell family. Nanny Tess is seeing things, and Ash's book debunking such phenomenon makes him a good choice to set her mind at ease and convince her she is just tired and stressed. But soon after arriving David too begins to doubt his senses, and watching the odd behavior of the three grown Mariell children doesn't make his task any easier. In fact, he begins to think Nanny Tess isn't really just tired and stressed out after all.

In the sixth year at Hogwarts School of Witchcraft, and in both wizard and muggle worlds Lord Voldemort and his henchmen are increasingly active. With vacancies to fill at Hogwarts, Professor Dumbledore persuades Horace Slughorn, back from retirement to become the potions teacher, while Professor Snape receives long awaited news. Harry Potter, together with Dumbledore, must face treacherous tasks to defeat his evil nemesis.

Set in the 1930's the story takes place in an old fashioned English country house where a family has invited many of their friends up for a weekend shooting party. The story centers around the McCordle family, particularly the man of the house, William McCordle. Getting on in years William has become benefactor to many of his relatives and friends. As the weekend goes on and secrets are revealed, it seems everyone, above stairs and below, wants a piece of William and his money, but how far will they go to get it?

Harry Potter is having a tough time with his relatives (yet again). He runs away after using magic to inflate Uncle Vernon's sister Marge who was being offensive towards Harry's parents. Initially scared for using magic outside the school, he is pleasantly surprised that he won't be penalized after all. However, he soon learns that a dangerous criminal and Voldemort's trusted aide Sirius Black has escaped from the Azkaban prison and wants to kill Harry to avenge the Dark Lord. To worsen the conditions for Harry, vile creatures called Dementors are appointed to guard the school gates and inexplicably happen to have the most horrible effect on him. Little does Harry know that by the end of this year, many holes in his past (whatever he knows of it) will be filled up and he will have a clearer vision of what the future has in store...

After a lonely summer on Privet Drive, Harry returns to a Hogwarts full of ill-fortune. Few of students and parents believe him or Dumbledore that Voldemort is really back. The ministry had decided to step in by appointing a new Defence Against the Dark Arts teacher that proves to be the nastiest person Harry has ever encountered. Harry also can't help stealing glances with the beautiful Cho Chang. To top it off are dreams that Harry can't explain, and a mystery behind something Voldemort is searching for. With these many things Harry begins one of his toughest years at Hogwarts School of Witchcraft and Wizardry.