Simon and I stared at the unscratched, stainless mirror bolted to the wall. One of us had to go first. One of us had to scout the Domain for traps while the other waited. We didn't discuss beforehand who'd go first. I didn't expect it to be an issue that couldn't be solved through a coin toss, but the half-open mouths and silent lips in our reflections suggested otherwise.

"Let me go first," Simon said.

"Why?" I asked.

"I don't think I'd be a good backup. Remember last time I was down here?"

"Simon, you did everything you could."

Simon removed a horseshoe and a crowbar before leaving me his backpack. "And it wasn't enough! Let me be useful, okay? We might die and I'd at least like to go out with dignity."

Simon walked through the mirror surface before I could respond. It was as if he were diving into a river. Soft ripples formed through his entrance and blurred the labyrinthine bookshelves he approached. He had disarmed himself. By leaving his iron-filled backpack behind, he made himself less threatening to the spirits and left me with weapons for backup. I hoped he wasn't about to regret his decision.

Although the arcane library was large, it was easy for me to see where he was. His blue robe stuck out so nicely from the black walls, the glowing torches, and the red book envelopes. He went behind each of the shelves, checking their corners for secret traps. Each time he returned into my field of vision, he was unharmed. No claw marks on his body or bloodstains on his clothes.

Yet, I never let my guard down. Once or twice a minute, I checked the boiler room and looked at my necklace's glow.

The waiting paid off. Simon returned to the mirror in one piece, beaming with joy. He showed me what he found: A piece of parchment and a book without a title.

The book first. I opened it and read its first paragraphs. "Once upon a time, there was a sheep with wool as soft as the cotton clouds and the innocence of the fairest maids. It was grazing under the gentle warmth of the morning Sun when the Big Bad Marissa came."

"Why is the villain of this book named after me?" I asked.

"What?" Simon asked. "The villain is called Simon. I picked it up because I found that funny."

I dropped the book like it was poison. A book that cast anyone who read it as the villain fit this day of the year a little too well.

Simon handed me the parchment. I made a photo of it and sent it to Marco (who was, hopefully, already on his way) before I started reading it.

"Dear reader,

"you might have heard unpleasant rumors about me, but I have my reasons for what I do. I wish to go against tradition by merging the natural and supernatural worlds. Your people deserve the truth about the nature of reality. The world of practitioners is full of supremacist fools who keep the masses ignorant. Unfortunately, the resistance I faced made a peaceful arrival impossible. After my Nuckelavee has overcome its psychological barriers and manifested in your world, I will follow. By the time you are reading this, it is likely All Hallows' Eve. Thanks to hundreds of generous supporters who offered me their names, the Headless Horseman will start the Wild Hunt in towns all across the northeastern United States. You can find a list of names if you flip the page.

"Yours Sincerely,

"The Erlking."

I flipped the page. My last name was near the bottom. And above it was Devons, Turner, and so many other names that he had to write small to fit them onto one page. Judging from the dates he added with little crosses, many of them died decades ago – even though the oldest murders linked to him were years old at most.

"Quite a lot, ain't it?" Simon asked. "I've looked at cases reported about him. He has a cool-down time of three to six months and he's been active for a few years. If you do the math-"

"It doesn't add up," I said. "That's hundreds of victims."

"Yep. Most of the people he killed never received any media attention. Many of their names don't even sound very English, let alone white and Anglo-Saxon."

Had this page not been so important, I'd have crumbled the paper in my hand.

"I'm telling you," Simon said, "these Hunters and Knights or whatever care more for maintaining order than what's right."

"It's not so simple," I said. "Dad told me that serial killer cases take so long to solve because most murderers know their victims. It's hard to connect random killings, let alone find the killer. The Erlking only got noticed once he started adding letters like this to his murders."

"Well, whatever," Simon said. "Do you also know anything about his motives?"

"Power," I said. "At the start of his career, he stole people's names, sold them to a higher entity, and bought influence over the Veil. At first, he couldn't do anything that'd get him caught. He only killed those no-one would miss, but he wasn't satisfied. He wanted more. He wanted to be remembered in history. The more people fear him, the more life energy he drains."

"Is that why he's gonna attack at Halloween with the Headless Horseman as backup?" Simon asked.

"Probably."

"How strong is this Horseman?"

"Well, he's about as famous as Dracula or Frankenstein and supernaturals can get power through awareness. I think he isn't a pushover."

"Can you look him up?"

I fished out my Magia Phone from my bag and scouted the Wiki. With no time to lose, I typed "Headless Horseman" into the search engine. It redirected me to a page titled "Dullahan". The page was as long as one might expect from such a famous supernatural, so I stuck to the infobox.

Name: Dullahan, Headless Horseman.

Alignment: Unseelie Kingdom

Classification: Godling

Threat assessment: C-rank when provoked. B-rank when near his Center of Worship.

Center of Worship: Ireland (earlier), Hudson Valley (after popularization through Washington Irving's The Legend of Sleepy Hollow).

Known abilities: Intangibility, reaping people's souls by speaking their names, calling up the Wild Hunt.

Countermeasures: Gold, avoiding provocation.

"Found anything?" Simon asked.

I showed him my phone so that he could read for himself.

Simon frowned. "Oh. The Hudson Valley is his Center of Worship?"

"Yes.

"And Summer Hill will be in the brunt of his Wild Hunt?"

"Yes."

"And how can I imagine this 'Wild Hunt'?"

"Bunch of Unseelie nasties and ghosts hunt around. Anyone who gets in the way must join the Hunt. There'll be a storm. Judging by the B-ranking, it'll make Hurricane Katrina proud"

Simon nodded mutely. "You're joking, right? You're joking. You're joking. There's no way he created something like this under our noses."

I felt a moment's trepidation.

Simon returned my phone.

"All because of the Veil," I muttered.

"What does that Veil have to do with this?"

"Everything," I said. "It's supposed to protect us, but it made supernaturals so good at hiding that no one noticed the Erlking's private Manhattan project."

"Yeah," Simon said. "We're going to die. Like, actually die."

My fingers shivered on my phone's screen. "I-I'll text our backup. He'll tell everyone else. You put as many iron nails in this basement as possible. Once we're done, we go to the dance and inform everyone."

"And this is going to help us how? This isn't his only Domain!"

"Simon, please! Don't give-"

I yawned. I suddenly saw Simon twice and the mirror behind him blurred. Where was the door? What did I even plan to do next? Good grief, that nocturnality potion was wearing off. It was like those antidepressants my therapist in New York City prescribed. They helped cure my anxiety issues, but they also caused confusion and headaches after withdrawal.

"Don't tell me you want to sleep now!" he said.

"Simon!" I said. "You said you wanted to help."

"Yeah. Back when I thought there was a way to help!"

"There is! You know what? Being useful doesn't mean having magic powers. Being useful means doing everything you can even when the odds are against you!"

Simon shrugged. He opened his backpack and threw nails at the ground. He added them to the nails dropped by Hunters who briefly volunteered as janitors at my school. They used them for wards, but wards fizzled out without life energy to maintain them. "Hope isn't something that lets us survive, but I guess you have a point," he said.

"Thanks," I said.

Man, this boiler room door felt so dark. Even with the faint, ever-burning light bulbs people so often forgot to switch off. Its water pots, buckets, ground pipes, and rests of moss whose origin none of the school staff knew got covered under a cloud of thick, foggy air.

Until someone opened the door and blinded me with the light of the outside world.

A girl stood in the doorway. With my tired, sleepwalking zombie brain, it took me two split seconds to recognize her. The red Victorian bodice dress, the inverted crosses on her sleeves, the iron pentacle around her neck, and the fake plastic vampire teeth fit her style. It was the open hair, the make-up, and her uncharacteristically serious expression that first disguised her from my sleepy mind.

"I hope I'm not interrupting anything between you two," Isa said.

I bit my lip. Although no demon had emotionally drained me this time and I didn't panic, I still felt terrible. Terribly tired. And terribly terrible because I forgot my serotonin inhibitors today. Which meant if I wanted to explain myself, my anxiety was an infinitely bigger issue than the Veil.

"It's not what you think it is!" Simon.

Isa folded her arms. "Just searchin' you since you didn't answer my messages. Again."

I could tell her the truth. Evil Siris made it possible for me without normal Siris stopping me. I needed to tell her about the Horseman and the Hunt and everything and the best way would have been to simply hand over the parchment. Unfortunately, I still felt tired and Simon was faster with his lips than I was.

"How did you find us here?" he asked.

"A few weeks ago, I told Mars she could meet Klaus Kringle here on Halloween," she said. "Going into a creepy basement, breaking the rules; who wouldn't want to do that? Any reason you didn't even think of telling me?"

"Are you becoming jealous or something?".

"Simon, that's not helping," I whispered.

"I'm not jealous," she said. "I'm just worried. You always look so tired and nervous and any time I try to talk to you about this, you evade me. Did I hurt you somehow?"

I swallowed a lump in my throat. "You didn't hurt me, Isa. Someone else did. The- the Erlking. I'm sure you heard about him in the news. He's real. And he'll kill us all."

She raised an eyebrow. "How do you know this? Have already called the police?"

"The police can't help us," I said. "This isn't the type of criminal you can put in handcuffs and throw in prison. Dad tried to do this and he almost got himself killed."

Isa froze, staring at us with fearful eyes. "What do you mean? What are you planning?"

I showed her the parchment. "You can call the police if you want. Simon and I are preparing something. When we're done, we're immediately going to run to the dance party and inform everyone!"

"Inform everyone?" she asked. "How long did you know all this?"

"Isa-"

"All those times you were tired, it was over this. I asked you and you didn't tell me. You lied to me!"

"I didn't lie to you!" I said. "There are other people who didn't want me to tell you."

"Other people?" she asked. "You mean, you two are in a cult?"

I eyed Simon, then her. "You could put it that way, even if it's more complicated than that."

Isa put her hand over her mouth. "Sorry to hear that. Does your Dad already know about this, we need to get you out of this."

"Yes," I said. "After we're done with this!"

It was then that I heard a scream outside.