That’s the given title for the last Harry Potter novel. No details on it yet, aside from JK Rowling’s statements about writing the novel, including her experience about having an “epic dream” where she was both Harry Potter and the Narrator. That’s interesting in that the Harry Potter novels have almost exclusively been told from Harry’s standpoint (the exceptions being the first few chapters of the sixth novel only). But then, the dream was more dreamlike than storylike:

The author says: “For years now, people have asked me whether I ever dream that I am ‘in’ Harry’s world.

“The answer was ‘no’ until a few nights ago, when I had an epic dream in which I was, simultaneously, Harry and the narrator.”

She says: “I was searching for a Horcrux in a gigantic, crowded hall which bore no resemblance to the Great Hall as I imagine it.”

So far, it seems like she’s in the Harry Potter novel…

“As the narrator I knew perfectly well that the Horcrux was jammed in a hidden nook in the fireplace, while as Harry I was searching for it in all kinds of other places, while trying to make the people around me say lines I had pre-arranged for them.”

…and we begin to see the author entering the dream. And then:

“Meanwhile waiters and waitresses who work in the real cafe in which I have written huge parts of book seven roamed around me as though on stilts, all of them at last 15ft high.”

She adds: “Perhaps I should cut back on the caffeine.”

…then it gets to look much more like the frenzied dream of a harried author under a demanding deadline. OK.

Of course, if one wants to read a fully-completed Harry Potter novel series, then read the first five published and then my brother’s sixth, seventh–and later, eighth novels to complement Rowling’s first five.