For Ages
8 to 12

Keys to the Demon Prison is a part of the Fablehaven collection.

OVER 3.5 MILLION COPIES SOLD IN SERIES! Celebrate the 20th anniversary of the beloved New York Times bestselling series about two siblings who inherit a hidden sanctuary for magical creatures. In the fifth installment of this worldwide phenomenon, time is running out to stop an army of demons from being unleashed on the world.

Hours of crisis often call for sacrifice.

After centuries of plotting, the Society of the Evening Star is closer than ever to opening the great demon prison and unleashing a tide of evil. And when the enemy strikes even closer to home—kidnapping Kendra and Seth’s parents—it kicks off the epic final showdown between the forces of light and darkness. 

While racing across the globe to secure the remaining artifacts with the Knights of the Dawn, Kendra and Seth are separated in the thick of battle. Kendra’s search to rescue her family takes her across time and space, from the Fablehaven of the past to a preserve so hidden that few even know of its existence. Meanwhile, Seth’s path brings him face to face with the Sphinx—the mastermind behind the Society—who gives Seth a dangerous choice that could change everything.

In this explosive series finale, allegiances will be tested and secrets will be revealed in a desperate battle to control the keys to the demon prison—and control the fate of the world. 

Don't forget to drink the milk. And definitely don’t miss any of Brandon Mull’s BEST-SELLING SERIES:

FABLEHAVEN BOOKS 1-5• DRAGONWATCH Books 1-5 • GUARDIANS (Coming in 2026!)

An Excerpt fromKeys to the Demon Prison

Chapter One

A Dying ­Wish

Seth knew he should not be here. His grandparents would be furious if they found out. The dismal cave smelled more rancid than ever, like a nauseating feast of spoiled meat and fruit. Almost steamy with humidity, the wet air forced him not only to smell but also to taste the putrid sweetness. Every inhalation made him want to ­retch.

Graulas lay on his side, chest swelling and shrinking with labored, hitching breaths. His infected face rested against the rocky floor, inflamed flesh flattened in a sticky mass. Although the demon’s wrinkly eyelids were shut, he twitched and grunted as Seth drew near. Groaning and coughing, the bulky demon peeled his face away from the floor, one curled ram horn scraping the ground. The demon did not fully arise, but managed to prop himself up on one elbow. One eye opened a fraction. The other was fused shut by congealed ­goo.

“Seth,” Graulas rasped, his formerly rumbling voice weak and ­tired.

“I came,” Seth acknowledged. “You said it was urgent.”

The heavy head nodded slightly. “I . . . am . . . dying,” he ­managed.

The ancient demon had been diseased and dying since Seth had first met him. “Worse than ever?”

The demon wheezed and coughed, a cloud of dust rising from his lumpy frame. After spitting out a thick wad of phlegm, he spoke again, his voice little more than a whisper. “After . . . long years . . . of dwindling . . . my final days . . . have arrived.”

Seth was unsure what to say. Graulas had never tried to hide his nefarious past. Most good people would be relieved to hear of his demise. But the demon had taken a liking to Seth. After becoming intrigued by Seth’s unusual exploits and successes, Graulas had helped him figure out how to stop the shadow plague, and had further assisted him in learning to use his newfound abilities as a shadow charmer. Whatever crimes Graulas may have committed in the past, the moribund demon had always treated Seth ­well.

“I’m sorry,” Seth said, mildly surprised to find he really meant ­it.

The demon trembled, then his elbow collapsed and he flopped flat against the ground. His eye closed. “The pain,” he moaned softly. “Exquisite pain. My kind . . . dies . . . so very slowly. I thought . . . I had sampled . . . every possible agony. But now, it burrows . . . twists . . . gnaws . . . expands. Deep inside. Relentless. Consuming. Before I can master it . . . the pain increases . . . to new plateaus of anguish.”

“Can I help?” Seth asked, doubting whether anything from the medicine cabinet would do the ­trick.

The demon snorted. “Not likely,” he panted. “I understand . . . you will leave tomorrow.”

“How did you know that?” His mission the next day was supposedly a ­secret.

“Confide . . . no plans . . . to Newel and Doren.”

Seth had not provided the satyrs with details. He had just told them he would be leaving Fablehaven for a time. He had been at the preserve for more than three months, ever since he and the others had returned from Wyrmroost. He had enjoyed several adventures with Newel and Doren in the interim, and felt he owed them a ­good-­bye. Grandpa would only let them discuss the mission in his office with spells to help prevent spying, so Seth had shared no specifics, but he probably should not have said anything at all to the satyrs. “I didn’t give them details,” he told ­Graulas.

“No . . . but I heard them mention your departure . . . as they moved about the woods. Although . . . I can’t see into your house . . . I can deduce . . . you seek another artifact. Only such . . . a mission . . . would prompt Stan to risk . . . your safety.”

“I can’t really talk about it,” Seth ­apologized.

Graulas coughed wetly. “The details are unimportant. If I heard and guessed . . . others may have heard. Though I cannot . . . see . . . beyond the preserve . . . I can sense much outside attention focused here. Mighty wills straining to spy. Be on your guard.”

“I’ll be careful,” Seth promised. “Is that why you called me here? To warn me?”

One eye cracked open and a faint smile touched the demon’s desiccated lips. “Nothing so . . . altruistic. I am soliciting a favor.”

“What?”

“I may . . . expire . . . before you return. Which would render my wishes . . . irrelevant. After all this time . . . my days are truly numbered. Seth . . . not only . . . my physical pain . . . troubles me. I am afraid to die.”

“Me too.”

Graulas grimaced. “You do not understand. Compared to me . . . you have little to fear.”

Seth scrunched his brow. “You mean because you were bad?”

“If I could . . . evaporate . . . into nothing . . . I would welcome death. But this is not the case. There are other spheres awaiting us, Seth. The place prepared for my kind . . . when we exit this life . . . is not pleasant. Which is partly why demons cling to this life for as long as we can. After how I lived . . . for thousands of years . . . I will have to pay a steep price.”

“But you’re not the person you were,” Seth said. “You’ve helped me a lot! I’m sure that will count for something.”

Graulas huffed and coughed differently than he had before. It almost sounded like a bitter chuckle. “I meddled with your dilemmas . . . from my deathbed . . . to amuse myself. Such trivialities will do little to offset centuries of deliberate evil. I have not changed, Seth. I am merely powerless. I have no drive left. As much pain as I am now enduring, I fear that the afterlife . . . will hold far greater agonies.”

“So what can I do?” Seth ­wondered.

“One thing only,” Graulas growled through clenched lips. His eye squinted shut and his fists tightened. Seth heard teeth grinding. The demon’s breath came in sharp, ragged bursts. “One moment,” he managed, trembling. Creamy tears oozed from his ­eyes.

Seth turned away. It was too much to watch. He had never imagined such misery. He wanted to run from the cave and never ­return.

“One moment,” Graulas gasped again. After a few grunts and moans, he began to breathe more deeply. “You can do one thing for me.”

“Tell me,” Seth ­said.

“I do not know the purpose of your mission . . . but should you recover the Sands of Sanctity . . . that artifact could greatly alleviate my suffering.”

“But you’re so diseased. Wouldn’t it kill you?”

“You’re thinking of . . . the unicorn horn. The horn purifies . . . and yes . . . its touch would slay me. But the Sands heal. They wouldn’t just burn away my impurities. The Sands would cure my maladies and help my body survive the process. I would still be dying of old age, but the pain would be lessened, and the healing might even buy me a little more time. Forgive me, Seth. I would not ask . . . were I not desperate.”

Seth stared at the pathetic ruin the demon’s body had become. “The Sphinx has the Sands,” he said ­gently.

“I know,” Graulas whispered. “Even the thought . . . that there is some small chance . . . gives me something to dwell upon . . . besides . . . besides . . .”

“I understand,” Seth ­said.

“I have nothing else to hope for.”

“Of course we’re trying to get the Sands back,” Seth soothed. “I can’t say this mission will do that, but of course we hope to recover all of the artifacts. If we can get the Sands of Sanctity, I’ll bring the artifact here and heal you. I promise. Okay?”

Discolored tears gushed from the eyes of the demon. He turned his face away. “Fair enough. You have . . . my thanks . . . Seth Sorenson. Farewell.”

“Is there anything else I can—”

“Go. You can do nothing more. I would rather not . . . be seen . . . like this.”

“Okay. Hang in there.”

Flashlight in hand, Seth exited the cave, relieved to leave behind the humid stench and the naked ­agony.