The magic of the Fablehaven

The Knights of the Dawn are in trouble.

Betrayals and treachery have taken their toll.

Vital artifacts have fallen into the hands of the Society of the Evening Star.

Family members have been kidnapped.

The demon prison Zzyzx is close to being opened, which will pretty much mean the end of the world as we know it — and poor Seth still can't seem to get it quite right.

Get ready for the biggest roller-coaster ride of the Fablehaven series, author Brandon Mull says.

"Fablehaven: Keys to the Demon Prison," the final installment in the best-selling series, will be released nationwide by Shadow Mountain on Tuesday. In Salt Lake City, a special free launch party will be held at Cottonwood High School that will include entertainment by a comedy troupe, dancers and Fablehaven characters. There will be face painting and other activities. And there will be a chance for fans to meet Mull and get his autograph.

Fablehaven, one of several secret preserves for all the magical creatures in the world, was first introduced in 2006, when Seth and Kendra discovered that their grandparents were keepers of this world.

As the series has progressed, dark forces have threatened not only the existence of the magical preserves but the very world itself. Seth, Kendra and the Knights of the Dawn have been called upon to battle demons, dragons and other evils. Friends have turned out to be foes; foes have turned into friends; good intentions have had disastrous results.

And now the forces are set for the final showdown.

"I'm very content with how it ended, and I hope readers will be, too," Mull says. "I think it ended well, and that's a huge relief."

Although he started with the general outline in his head, putting it all down on paper is another thing altogether, he says. In fact, he has so much in his head, "I have to make sure I haven't left anything out, that it all connects. That's why I have editors."

But over the course of the series, "the characters get easier to write. They become so familiar, they almost write themselves."

That's comforting, he says, but can't be taken for granted. "The characters are what brings the story to life; they are the heart of the story. The relationship between Seth and Kendra, that's what matters most, what makes the story believable."