Some kids might have trouble understanding how two boys could find themselves trapped on a narrow ledge outside their school and forty feet off the ground.

Of course, these same kids have probably never been trapped in their lockers by giant tentacled beasts. Or trapped in their bedrooms with boa constrictors. Or trapped underground with thousands of chirping and chattering insects.

But for Robert Arthur and Glenn Torkells, these kinds of near-death experiences were all just a regular part of seventh grade.

A few months earlier, the boys had discovered that Lovecraft Middle School was constructed from the recycled remains of Tillinghast Mansion—a crumbling estate that was once home to the mad physicist Crawford Tillinghast. Because of a botched experiment, the mansion still existed in a parallel dimension; Robert and Glenn could pass from the school to the mansion and back again through hidden portals called “gates.”

The boys soon learned that Tillinghast was capturing teachers and students, placing their souls in ceramic urns, and then using their flesh and hair as disguises for an army of bizarre monsters. The school was slowly being infiltrated by demons, snake-people, giant insects, and other ancient creatures summoned from distant dimensions.

Armed with this knowledge, Robert and Glenn went to school every day determined to stop Tillinghast and always expecting the worst. Yet nothing could have prepared them for the strange events of February fourteenth.

The day began with an announcement from the principal inviting all students to a surprise Valentine’s Day concert by the music department. As Robert followed his classmates into the auditorium, teachers gave out programs listing all the songs.

Glenn read the titles aloud in disbelief. “ ‘Love Me Tender’? ‘Eternal Flame’? ‘You Are the Sunshine of My Life’?” He crumpled the program into a ball. “This is going to be torture!”

“Well, don’t spoil it for the rest of us,” said Karina Ortiz. “Robert and I are looking forward to it.”

“Are you kidding me?” Glenn said, laughing. “Robert hates Valentine’s Day even more than I do!”

Robert just shrugged. A year ago, he would have agreed with Glenn that Valentine’s Day was a dumb holiday designed to sell overpriced chocolates. But since arriving in seventh grade—and meeting Karina—his feelings had changed. Karina loved Valentine’s Day and she was one of the coolest people Robert had ever met, so how bad could it really be?

The kids found seats at the back of the auditorium, far from their classmates.

“Well, I don’t care if you like it or not,” Karina continued. “I got you both presents, anyway.” She whistled for Robert’s pets, a two-headed rat named Pip and Squeak. They wriggled out of his backpack carrying two chocolate hearts wrapped in red foil. “One for each of you.”

The rats crawled onto the armrest, passing out the gifts and happily chattering their teeth.

“Thanks,” Robert said. “How did you get these?”

“Second-floor vending machine,” she said. “Pip and Squeak fished them out for me.”

Glenn studied his candy and discovered the rats had already taken a huge bite from it. He unwrapped the foil and ate the rest of the chocolate, anyway. “Isht preddy goot,” he said, chewing through the caramel center. “Thanks.”

Robert and Glenn were the only ones who knew that Karina had been dead for thirty years and that her spirit was confined to the property of Lovecraft Middle School. She may have looked and acted like a regular seventh-grade girl, but in truth she couldn’t hold a pencil or even turn on a computer. That was why she did all of her holiday shopping from school vending machines, with a little assistance from a two-headed rat.

Karina looked pointedly to Robert, as if she were expecting a gift in return. Fortunately for him, the houselights dimmed just in time.

“The show’s starting,” he said.

High above the stage, a giant cardboard Cupid descended from the rafters; it was dressed in a diaper and holding a bow and arrow. A handful of students applauded, but Glenn just moaned. “Let the torture begin.”

“Shhhh,” Karina said.

He pulled on his hood and slumped in his chair. “Wake me when it’s over.”

The boys and girls chorus walked on stage singing “Can You Feel the Love Tonight?” from The Lion King, and their soaring voices drowned out Glenn’s complaints. Karina leaned forward in her chair, enchanted by the performance. After thirty years of confinement in Tillinghast Mansion, she enjoyed any chance to be a regular kid again. She was delighted by all of the everyday things that Robert took for granted: surprise fire drills, the smell of freshly sharpened pencils, and especially school assemblies.

Pip and Squeak were enjoying the concert as much as Karina, maybe even more. They sat perched on Robert’s shoulder, swaying back and forth, dancing to the music.

Suddenly, Glenn sat up straight in his chair.

“I thought you were napping,” Robert said.

He pointed at the stage. “Look what they’re wearing!”

Robert was confused. The members of the chorus were dressed in shiny red robes. “What’s the big deal?”

“They’re the same robes from the mansion! The cloaks worn by Tillinghast’s servants!”

Karina blinked. “Oh my gosh. He’s right.”

“So what?” Robert asked.

“If we got some,” Glenn continued, growing excited, “I bet we could explore the whole mansion without getting caught. We could disguise ourselves as servants. Maybe we’d find a way to close the gates once and for all!”

“Maybe,” Robert said, but Glenn was already standing up and gathering his things. “Where are you going?”

“To the Music Room.”

“Right now?”

“We’ll never have a better chance,” Glenn said. “Everyone’s here watching the show!”

“I’m not going anywhere,” Karina said, crossing her arms over her chest. “The concert just started.”

Pip and Squeak leapt onto her armrest and nodded their heads. They weren’t going anywhere, either.

Glenn turned to Robert. “What’s more important?” he asked. “A stupid Valentine’s Day concert or saving the world from an army of ancient monsters?”

When Glenn put the question that way, Robert felt as though he had no choice. “I guess saving the world.”

“I’ll save your seats,” Karina offered. “Have fun.”

Robert and Glenn slipped out the back door and went straight to the Music Room, a large rehearsal space cluttered with folding chairs and music stands. Perched on a shelf were white marble busts of Mozart and Beethoven. Apart from the two famous composers, the boys had the whole space to themselves.

Glenn opened a door marked WARDROBE and they entered a cramped, narrow passage. It was flanked by theater costumes, marching band uniforms, and—all the way in the back—a rack of abnormally sized chorus robes. Glenn flipped through the hangers, checking the tags. “They’ve got extra-small or extra-extra-large,” he said. “Which do you want?”

Robert glanced around anxiously. He worried that one of the music teachers would catch them red-handed. “I don’t care,” he whispered. “You pick.”

Glenn grabbed a 2XL, pulled it over his head, and fit his arms through the sleeves.

“Why are you putting it on?” Robert asked.

“We’re taking a test-drive,” Glenn said. “Look.”

He parted the robes, creating a gap in the middle of the clothes rack. Hidden behind the gowns was a small whirling vortex: a new gate into Tillinghast Mansion.

“No way,” Robert said. “We can’t ditch Karina at the concert. She’s waiting for us.”

“We’ll be back in five minutes,” Glenn promised. “I only want to take a quick peek. To see where we end up. If there’s any trouble—”

“There’s always trouble. Every time we cross over, something tries to eat us.”

“If we see anything dangerous, we’ll come right back.”

Robert didn’t share any of Glenn’s curiosity. He had no desire to return to Tillinghast Mansion. The house was a giant labyrinth of cobwebbed corridors, twisting stairs, and mysterious passages. All of its doors were identical and unmarked, so it was impossible for visitors to find their way, and strange creatures lurked around every corner. Robert would have been much happier listening to love songs from The Lion King.

But Glenn insisted on going, and Robert couldn’t let his best friend cross over alone. There was no telling what might happen if he did.

“Five minutes,” he said. “Not a second more.”

Robert pulled a robe over his head and wiggled his arms through the sleeves. The fabric hung past his fingertips, but it would have to do.

Glenn sat down on a box and unlaced his boots. “Don’t forget to take off your shoes,” he said. “All the servants walk barefoot.”

“Right.” He pulled off his sneakers and socks and tucked them with his backpack under a shelf.

“See you in the mansion,” Glenn said, and then he ducked between the robes and tumbled into the vortex.

Robert took one last look around the closet, nagged by a sense that he was making a terrible mistake.

Then he stepped into the gate, anyway.