Tanu nodded.

The back door opened, and Dale entered with Mendigo.

"What's going on?" Dale asked, taking in Tanu's altered state. "Mendigo showed up at the stables and abducted me."

"We have a problem," Grandpa said. "Dark fairies attacked Seth in the yard."

Eyes wide, Tanu gestured vigorously.

"Dark fairies attacked you too?" Seth asked.

Tanu stabbed a finger at Seth, nodding emphatically.

"Have you noticed anything unusual with any of the creatures today?" Grandpa asked Dale.

"Nothing like dark fairies," he replied.

"I called Ruth. She'll be careful coming into the house. I still can't reach the Sphinx."

"When will he solidify?" Dale asked, his eyes flicking over to Tanu.

"In a few minutes," Grandpa said.

"Mind if I grab some water?" Dale asked.

"Might do us all some good," Grandpa said.

They went to the kitchen, where Dale poured each of them a tall glass of cool water from the fridge. While Seth sipped at his drink, Tanu coalesced into his old self. A brief fizzing sound accompanied the rapid transformation.

"Sorry about that," Tanu said. "I'm not sure I would have escaped without the aid of a potion."

"What happened?" Grandpa asked calmly.

Tanu took a sip of water. "As planned, we were scouting for a new home for the gentle nipsies. We were investigating that crescent-shaped meadow near where the Forgotten Chapel used to stand. You know the one?"

"Sure," Dale said.

Grandpa nodded.

"I would, if I was ever allowed to explore," Seth grumbled.

"We came across a swarm of squabbling fairies, weaving around like dogfighters, some light, some dark. From what we saw, when the dark ones got their mouths on the light ones, the light fairies were extinguished-they became dark. But the light fairies didn't appear to be converting any dark ones."

"How many fairies?" Grandpa asked.

"Must have been nearly thirty," Tanu answered. "The brawl looked about even at first, but before long, the dark outnumbered the light three to one. Coulter and I decided we ought to break it up before all the fairies were changed. He has that crystal that makes people dizzy, and thought he might be able to disrupt the battle enough to give the light fairies a chance to escape.

"The instant we stepped into the clearing, the dark fairies left off tangling with the light ones and swarmed us. There was almost no time to think. Coulter urged me to go gaseous. Hugo put himself between us and the onslaught, and they hit him hard with murky magic that withered the grass on his body and left him spotted with black marks. Holding his crystal high, Coulter ordered Hugo to retreat to the barn, which was the right call. There was little Hugo could do against so many tiny enemies. The golem obeyed, and the fairies swooped at Coulter. The crystal disrupted their flight. Most crashed to the ground. A few managed to land on Coulter. They started biting him, and then he vanished."

"Did he put on his invisibility glove?" Seth asked hopefully.

"No glove," Tanu said. "He just disappeared. I drank the potion as the fairies came at me, and dissolved into a gaseous state just in time. They were mad, darting through me, shooting bursts of blackness at me, but when they saw that it was in vain, they flew away."

"They couldn't have killed Coulter," Dale said. "Dark or, not, the treaty would still bind them. You were on neutral ground. They couldn't kill Coulter unless he had killed somebody at Fablehaven."

"For that very reason, I don't think he's dead," Tanu said. "But they placed some sort of curse on him that either made him invisible or teleported him away. I stayed and scoured the area, but found no evidence that he was invisible. No depressions in the grass where he might have been lying or standing. I would have heard him if he made a sound, but I detected nothing. That's all I know. I came straight here."

"You're sure Coulter didn't change into a darkened state himself?" Grandpa asked. "He simply vanished?" "That's what I saw," Tanu said. "Maybe he turned into grass, or into a mosquito, or into oxygen. Maybe he shrank. I suppose there's a chance that somehow the rules don't apply to these dark creatures, and Coulter no longer exists in any form."

Grandpa sighed, bowing his head. When he raised it, he looked wretched. "I worry that I'm unfit to continue as caretaker. Have I grown too old? Have I lost my touch? Perhaps I should resign and ask the Conservators' Alliance to appoint a new overseer in my stead. It seems we've had one catastrophe after another lately, with the people I love most paying the price for my incompetence."

"This isn't your fault," Tanu said, resting a hand on his shoulder. "I know you and Coulter are old friends."

"I'm not asking for sympathy," Grandpa said. "I'm simply trying to be objective. I've been captured twice in the past year. The preserve was taken to the brink of collapse each time. I may have become more of a hindrance than a help to Fablehaven and those who live here."

"A fellow can't always avoid tough circumstances," Dale said. "But you can weather the trouble and come out on top. You've done it before, and I expect you'll do it again."

Grandpa shook his head. "I haven't solved anything lately. If not for my grandchildren risking their lives, along with help from the rest of you and a healthy dose of good fortune, Fablehaven would be in ruins."

Seth had never seen Grandpa Sorenson look so defeated. How could he revive him? He spoke up quickly. "The first time, I caused all the trouble. The second time, Vanessa betrayed us. You never did anything wrong."

"And this time?" Grandpa asked, his voice calm and sad. "Not only did I inadvertently let your sister end up on a dangerous mission thousands of miles away, I also sent my oldest friend to his grave. How did I miss the warning signs?"

"The only thing that could make you unfit to lead would be belief in such nonsense," Tanu said gently. "Nobody could have seen this coming. You think Coulter or I would have approached the fairies so haphazardly had we sensed the danger? These are turbulent times. Fablehaven has been under deliberate assault from formidable foes. You've come through it so far, and so have we. I've traveled far and wide, and I can't think of anybody I would rather have watching over this preserve than you, Stan."

"I'll second that," Dale said. "Don't forget who'd most likely end up assigning the new caretaker if you resigned without appointing a successor."

"The Sphinx?" guessed Seth.

"His is the most trusted voice among the conservators," Grandpa admitted.

"Coulter is probably alive somewhere," Tanu said. "Pull yourself together, Stan. We need a plan."

"Thanks, Tanu, Dale, Seth." Grandpa pursed his lips, his eyes hardening. "We need information. The Sphinx is proving to be unreachable. Given the extremity of our circumstances, I think it's time to investigate what else Vanessa knows." Slaggo and Voorsh led a skinny, birdlike humanoid down the dank dungeon corridor. The manacled prisoner had a head like a seagull and was covered with gray, molting feathers. Slaggo held a torch, and Grandpa walked alongside, shining a flashlight on the threesome. When the flashlight beam strayed too high, reflecting off the birdman's beady black eyes, he threw his head back and let out a fierce squawk. Voorsh yanked on a chain fastened to an iron collar, making the grungy birdman stumble sideways. Grandpa switched off the flashlight.

"Ready?" Grandpa asked, eyeing Tanu, Dale, and Grandma. Tanu held handcuffs, Dale clutched a truncheon, and Grandma gripped a crossbow. They each gave a single nod.

Grandpa opened the front of the Quiet Box, revealing an empty space where a person could stand. The goblin wardens guided the birdman into the compartment. Grandpa closed the door and the box rotated halfway around, exposing an identical door on the opposite side. Grandpa opened the door and revealed Vanessa standing inside, wearing one of Grandma's old housecoats, a faint smile on her lips, the torchlight accenting her elegant features. Her skin had less color than the last time Seth had seen her, but her dark eyes smoldered. He had to admit she remained strikingly beautiful.

"How long has it been?" she asked, stepping out of the box and extending her hands so Tanu could cuff them. "Six weeks," Grandpa said, as Tanu secured the handcuffs.

"Where are my animals?"

"We released some," Grandpa said. "Others we gave away to those capable of caring for them."

Vanessa nodded as if satisfied. Her faint smile stretched into a smirk. "Let me guess. Kendra is no longer here, and some disaster is transpiring at Fablehaven."

Grandpa and Grandma exchanged a wary glance. "How did you know?" Grandma asked.

Vanessa stretched her cuffed hands high above her head and arched her back. She closed her eyes. "Certain precautions the Sphinx takes are predictable once you understand how he operates. It's the same way I anticipated that he was going to backstab me and lock me away in that miserable box."

"How did you predict this?" Grandpa asked.

Keeping her legs straight, Vanessa bent forward and touched the ground between her feet. "You released me from the box, and you all look serious, so obviously there has been trouble. Consider the circumstances. The Sphinx cannot afford to let his identity as the leader of the Society of the Evening Star be discovered. Even without the note I left, there were enough clues to what he was doing that you might have eventually become suspicious. He successfully acquired the artifact and freed the previous occupant of the Quiet Box. He had no more use for this preserve. Therefore, his next move would probably be to set some plan in motion to destroy Fablehaven and all of you with it-except Kendra, who he suspects may still be useful. I'm sure he created an excuse to get her away from here just in time. You're all in tremendous danger. You see, when the Sphinx commits a crime, he disposes of all the evidence. Then, to be safe, he burns down the neighborhood." Vanessa swung her handcuffed arms from side to side, twisting at her waist. "I can't tell you how nice it feels to stretch."

"Can you guess how he is trying to destroy Fablehaven?" Grandpa asked.

Vanessa arched an eyebrow. "Some of the Sphinx's strategies are predictable. His methods are not. But whatever he has set in motion will probably be impossible to stop. Fablehaven is doomed. I expect I would be safer if you just put me back in the Quiet Box."

"Don't worry, Vanessa," Grandma said. "We will."

"I take it you don't fully comprehend the current threat?" Vanessa asked Grandpa.

"It is like nothing we've ever seen."

"Tell me about it; maybe I can help. I've been working for the Society for some time now." Vanessa started jogging in place, lifting her knees high.

"Creatures at Fablehaven are turning dark," Grandpa said. "The change has been most evident in the nipsies and fairies so far-creatures of light who are transforming in appearance and attitude into creatures of darkness. I'm not talking about fairies falling and becoming imps. We've seen fairies draped in shadow using their magic to wither and ruin rather than to nourish and beautify." "And the condition is spreading?" Vanessa asked, legs pumping rapidly.

"Like a magical plague," Grandpa said. "Making matters worse, the dark fairies can cross all the same boundaries as the light fairies, including into the yard."

An expression of admiration appeared on her face. "Leave it to the Sphinx to invent new ways to eradicate preserves. I've never heard of an epidemic like you're describing. Let me guess. Even doubting the Sphinx, you've turned to him for help, but heard nothing."

Grandpa nodded.

"He is not replying because he expects you will soon be dead. You have two options. Abandon the preserve. Or try to figure out how to stop this plague the Sphinx has created, fail, and then abandon the preserve. My guess is you'll go with the second choice."

"Abandoning Fablehaven is not an option," Grandpa said. "Not until we do all we can to save it. Certainly not until we learn the secret behind this plague so we can prevent it from recurring elsewhere."

Vanessa stopped high-stepping, panting lightly.

"Whether or not you can salvage Fablehaven, trying to discover the nature of the plague makes sense. Any leads?"

"Not yet," Grandpa said. "Only today did we realize how virulently the condition is spreading."

"I could help if you let me," Vanessa offered. "Magical creatures are my specialty."

"Along with controlling victims in their sleep," Grandma reminded everyone. "You could post a guard," Vanessa suggested.

"We promised ourselves before we opened the box that you would be going back inside," Grandpa said.

"Very well, when all else fails and you change your minds, you'll know where to find me," she said. "The Quiet Box isn't as bad as I expected, really. After standing there waiting in the darkness for a while, you slip into a trance. Not full sleep, but you shut down, lose all sense of time. I was never hungry or thirsty-although I could use a drink now."

"Can you offer us sure evidence that the Sphinx is a traitor?" Grandma asked.

"Proof will be hard to come by. I know the names of other traitors. I was not the only one to infiltrate the Knights of the Dawn. And I know one secret that would absolutely blow your minds. But of course I'll divulge further information along those lines only in exchange for my freedom. Where is Kendra, by the way?" She asked the question with pretended innocence.