amplifying the water’s roar and making me feel like we were standing inside an old-fashioned root-beer keg. Supplies and baggage lined the dock, just waiting for a ship to be put on.

  At the far end of the room, Thomas Jefferson Jr. stood deep in conversation with the hotel manager, Helgi, and his assistant, Hunding, all three of them looking over some paperwork on a clipboard. Since I had an aversion to paperwork and also to Helgi, I walked over to Mallory, who was now stuffing iron grappling hooks into a burlap sack.

  She was dressed in black furs and black denim, her red hair pulled back in a severe bun. In the torchlight, her freckles glowed orange. As usual, she wore her trusty pair of knives at her sides.

  “Everything good?” I asked, because clearly it wasn’t.

  She scowled. “Don’t you start, too, Mister—” She called me a Gaelic term I didn’t recognize, but I was fairly sure it didn’t mean dearest friend. “We’ve been waiting on you and the boat.”

  “Where are Blitzen and Hearthstone?”

  It had been several weeks since I’d seen my dwarf and elf buddies, and I’d been looking forward to them sailing with us. (One of the few things I was looking forward to.)

  Mallory grunted impatiently. “We’re picking them up on the way.”

  That could have meant we were stopping by a different part of Boston, or stopping by a different world, but Mallory didn’t look like she was in the mood to elaborate. She scanned the space behind me and scowled. “What about Alex and Samirah?”

  “Alex said they’d meet us later.”

  “Well, then.” Mallory made a shooing gesture. “Go sign us out.”

  “Sign us out?”

  “Yeah…” She drawled the word to indicate just how slow she thought I was. “With Helgi. The manager. Off you go!”

  Since she was still holding a fistful of grappling hooks, I did what she told me.

  T.J. had his foot planted on a supply box, his rifle across his back. The brass buttons gleamed on his Union Army coat. He tipped his infantry cap at me in greeting. “Just in time, my friend!”

  Helgi and Hunding exchanged nervous looks, the way they did whenever Odin announced one of his motivational staff retreats.

  “Magnus Chase,” Helgi said, tugging at his roadkill beard. He was dressed in his usual dark green pinstripe suit, which he probably thought made him look like a service-industry professional, but only made him look like a Viking in a pinstripe suit. “We were beginning to worry. The high tide will be here any minute.”

  I looked at the water raging down the canal. I knew that several subterranean rivers wove their way through Valhalla, but I didn’t understand how they could be subject to tides. I also didn’t see how the water level here could get any higher without flooding the entire room. Then again, I was having a conversation with two dead Vikings and a Civil War soldier, so I decided to give logic a rest.

  “Sorry,” I said. “I was…”

  I waved vaguely, trying to indicate reading mysterious journals, killing wolves, breaking my leg in Boston Harbor.

  T.J. practically vibrated with excitement. “You got the boat? I can’t wait to see it!”

  “Uh, yeah.” I started rummaging in my knapsack, but the handkerchief seemed to have fallen to the bottom.

  Hunding wrung his hands. His bellhop uniform was buttoned wrong, like he’d rushed to get dressed this morning. “You didn’t lose it, did you? Oh, I warned you about leaving unattended magic items in your room! I told the cleaning ravens not to touch it. ‘It’s a warship!’ I said. ‘Not a napkin!’ But they kept wanting to launder it with the linens. If it’s missing—”

  “Then you’ll be held responsible,” Helgi snarled at the bellhop. “Floor nineteen is your service area.”

  Hunding winced. He and Helgi had a feud that went back several centuries. The manager welcomed any excuse to make Hunding work extra shifts shoveling garbage into the incinerators or hosing out the lindworm warrens.

  “Relax.” I pulled out the piece of cloth. “See? Here it is. And, Hunding, this is for you.” I handed him one of my chocolate bars. “Thanks for keeping an eye on my room while I’m gone.”

  The bellhop’s eyes turned misty. “Kid, you’re the best. You can leave unattended magic items in your room anytime!”

  “Hmph.” Helgi scowled. “Well, then, Magnus Chase, I’ll need you to sign out.” He thrust the clipboard at me. “Read carefully and initial at the bottom of each page.”

  I flipped through a dozen pages of dense contract language. I skimmed over phrases like In the event of death by squirrel attack and The proprietor shall not be held liable for off-site dismemberment. No wonder my friends preferred to leave the hotel without permission. The release forms were brutal.

  T.J. cleared his throat. “So, Magnus, maybe while you’re doing that, I could set up the boat? Can I? I’m ready to get this regiment underway!”

  I could tell. He was loaded down with enough ammunition pouches, haversacks, and canteens for a thirty-day march. His eyes gleamed as brightly as his bayonet. Since T.J. was usually the voice of reason on floor nineteen, I was glad to have him along, even if he did get a little too excited about full frontal charges on enemy positions.

  “Yeah,” I said. “Sure, man.”

  “YAY!” He plucked the handkerchief out of my hand and hustled toward the dock.

  I signed the release forms, trying not to get hung up on the clauses about arbitration in case we got incinerated in the fires of Muspellheim or got pulverized by frost giants. I handed the clipboard back to Helgi.

  The manager frowned. “You sure you read everything?”

  “Uh…yeah. I’m a fast reader.”

  Helgi gripped my shoulder. “Then good luck, Magnus Chase, son of Frey. And remember, you must stop Loki’s ship Naglfar from sailing at Midsummer—”

  “I know.”

  “—or Ragnarok begins.”

  “Right.”

  “Which means our renovations to the banquet hall won’t ever be complete, and we’ll never get high-speed Internet restored on floor two hundred forty-two.”

  I nodded grimly. I did not need the extra pressure of being responsible for an entire floor’s Internet connection. “We’ll succeed. Don’t worry.”

  Helgi tugged at his beard. “But if you do start Ragnarok, could you please get back here as soon as possible, or send us a text?”

  “Okay. Um, a text?”

  As far as I knew, the hotel staff just used ravens. They didn’t know how to use mobile devices. None of them even had numbers. But that didn’t stop them from talking a good game.

  “We’ll need to get everyone started on their checkout surveys before we march off to Doomsday,” Helgi explained. “To expedite their deaths. If you can’t make it back, you can also fill out your survey online. And if you wouldn’t mind marking excellent wherever it mentions the manager, I’d appreciate it. Odin does read those.”

  “But if we’re all going to die anyway—”

  “Good man.” He patted my shoulder. “Well, have a safe—er, successful journey!”

  He tucked the clipboard under his arm and strolled off, probably going to inspect those renovations to the banquet hall.

  Hunding sighed. “That man has no sense. Thanks for the chocolate, though, my boy. I just wish there was something more I could do for you.”

  My scalp tingled with inspiration. During my time at the hotel, Hunding had become my best source of information. He knew where all the bodies were buried (literally). He knew all the secret room service menu items, and how you could get from the lobby to the observation deck above the Grove of Glasir without having to pass through the gauntlet of gift shops. He was a walking Vikingpedia.

  I pulled out Randolph’s journal and showed him the last page. “Any idea what this word means?” I pointed to mjöð.

  Hunding laughed. “It says mead, of course!”

  “Huh. So it has nothing to do with cows.”

  “Pardon?”

/>   “Never mind. What about this name here—Bolverk?”

  Hunding flinched so violently he dropped his chocolate bar. “Bolverk? NO. No, no, no. What is this book, anyway? Why would you possibly—?”

  “Argh!” Halfborn yelled from dockside. “Magnus, we need you over here, now!”

  The river was starting to surge, frothing and lapping over the edge of the canal. T.J. shook the handkerchief desperately, yelling, “How does it work? How does it work?”

  It hadn’t occurred to me that the foldable ship, being a gift from my dad, might only work for me. I ran over to help.

  Mallory and Halfborn were scrambling to gather their supplies.

  “We’ve got a minute at most before the high tide comes flooding through here!” yelled Halfborn. “Ship, Magnus! Now!”

  I took the handkerchief and tried to steady my shaking hands. I’d practiced this ship-unfolding trick a couple of times on calmer water, once by myself and once with Alex, but I could still hardly believe it would work. I definitely wasn’t looking forward to the results.

  I flicked the handkerchief toward the water. As soon as the cloth hit the surface, the corners unfolded and unfolded and kept unfolding. It was like watching the building of a Lego model in a sped-up stop-motion video. In the space of two breaths, a Viking longship lay at anchor in the canal, the turbulent water coursing around its stern.

  But, of course, nobody complimented me on its beautifully trimmed hull, or the elaborate Viking shields lining the rails, or the five rows of oars ready for service. No one noted how the mainmast was hinged and folded over so it could pass through this low tunnel without breaking apart. No one gasped at the beauty of the carved dragon figurehead, or praised the fact that the ship was much larger and more spacious than your typical longship, even boasting a covered area belowdecks so we wouldn’t have to sleep in the rain and snow.

  Mallory Keen’s first comment was, “Can we talk about the color?”

  T.J. frowned. “Why is it—?”

  “I don’t know!” I wailed. “I don’t know why it’s yellow!”

  My father, Frey, had sent me the boat weeks ago, promising that it was the perfect vessel to use on our voyage. It would get us where we needed to go. It would protect us on the most treacherous seas.

  My friends had been excited. They had trusted me, even when I’d refused to give them a preview of our magical ship.

  But why, oh, why had my father made the boat the color of I Can’t Believe It’s Not Butter!®?

  Everything about it was neon, eye-melting yellow: the ropes, the shields, the hull, the sail, the rudder, even the dragon figurehead. For all I knew, the bottom of the keel was yellow, too, and we’d blind every fish we sailed past.

  “Well, it doesn’t matter now,” Halfborn said, scowling at me like it mattered very much. “Load up! Hurry!”

  A roar echoed from the upstream tunnel like an approaching freight train. The ship banged against the dock. Halfborn tossed our supplies on deck as T.J. hauled up the anchor, while Mallory and I held the mooring lines fast with all our einherji strength.

  Just as Halfborn threw the last sacks, a wall of water burst out of the tunnel behind us.

  “Let’s go!” yelled T.J.

  We jumped aboard as the wave slammed into our stern, propelling us forward like the kick of a seventy-million-gallon mule.

  I glanced back at the dock one last time. Hunding the bellhop stood knee-deep in water, clutching his chocolate bar, staring at me as we rocketed into the darkness, his face bleached with shock as if, after all these centuries of dealing with the dead in Valhalla, he’d finally seen an actual ghost.

  I LIKE my rivers the way I like my enemies—slow, wide, and lazy.

  I rarely get what I like.

  Our boat shot down the rapids in near-total darkness. My friends scrambled around the deck, grabbing ropes and tripping over oars. The ship rocked from side to side, making me feel like I was surfing on a pendulum. Mallory hugged the rudder with her full weight, trying to keep us in the middle of the current.

  “Don’t just stand there!” she yelled at me. “Help!”

  The old saying is true: no nautical training survives first contact with the water.

  I’m pretty sure that’s an old saying.

  Everything I’d learned from Percy Jackson evaporated out of my brain. I forgot starboard and port, stern and aft. I forgot how to discourage shark attacks and how to fall off a mast properly. I hopped across the deck yelling, “I’m helping! I’m helping!” without knowing what to do at all.

  We swerved and sloshed through the tunnel at impossible speeds, our retracted mast barely clearing the roof. The tips of our oars scraped against the stone walls, leaving trails of bright yellow sparks that made it look like faeries were ice-skating alongside us.

  T.J. rushed past me, heading for the prow, and nearly impaled me with his bayonet. “Magnus, hold that line!” he yelled, waving at pretty much every rope on the ship.

  I grabbed the nearest bit of rigging and pulled as hard as I could, hoping I had the right line, or hoping I at least looked helpful while doing the wrong thing.

  We bumped down a series of cataracts. My teeth clattered out telegraph messages. Frigid waves crashed over the shields on the railing. Then the tunnel widened and we sideswiped a rock that came out of nowhere. The boat spun a 360. We dropped down a waterfall toward certain death, and as the air turned to cold misty soup around us…everything went dark.

  What a fantastic time to have a vision!

  I found myself standing on the deck of a different ship.

  In the distance, glacial cliffs rimmed a vast bay marbled with ice. The air was so cold, a layer of frost crackled over my coat sleeves. Beneath my feet, instead of wooden planking, spread a bumpy surface of glistening gray and black like the shell of an armadillo.

  The entire ship, a Viking vessel the size of an aircraft carrier, was made of the same stuff. And unfortunately I knew what it was—the clipped toenails and fingernails of the dishonored dead, billions upon billions of nasty zombie cuttings, all cobbled together by evil pedicurist magic to create Naglfar, the Ship of Nails, also known as the Ship of the Dead.

  Above me, gray sails rippled in the freezing wind.

  Shuffling across the deck were thousands of desiccated human husks dressed in rusted armor: draugr, Viking zombies. Giants strode among them, shouting orders and kicking them to form ranks. Out of the corners of my eyes, I caught glimpses of darker things, too: incorporeal shades that might have been wolves, or serpents, or skeletal horses made of smoke.

  “Look who’s here!” said a cheerful voice.

  Standing before me, in the white uniform of a navy admiral, was Loki himself. His autumn-leaf-colored hair swept around the edges of his flag officer’s hat. His intense irises glinted like rings of hardening amber, suffocating the life out of his poor trapped pupils. Despite the pitted wreckage of his face, damaged from centuries of snake venom dripping between his eyes, despite the scarred and twisted lips that had once been sewn together by an angry dwarf, Loki grinned in such a warm, friendly way it was almost impossible not to smile back.

  “Coming to visit me?” he asked. “Awesome!”

  I tried to yell at him. I wanted to berate him for getting my uncle killed, for torturing my friends, for ruining my life and causing me six solid months of indigestion, but my throat was filled with wet cement.

  “Nothing to say?” Loki chuckled. “That’s all right, because I’ve got plenty to tell you. First a friendly warning: I’d really think twice about following old Randolph’s plan.” His expression tightened with false sympathy. “I’m afraid the poor man got a little senile there toward the end. You’d have to be crazy to listen to him!”

  I wanted to strangle Loki, but my hands felt strangely heavy. I looked down and saw that my fingernails were growing at unnatural speed, stretching toward the deck like taproots seeking soil. My feet felt too tight in my shoes. Somehow I knew that my toenails were also l
engthening, pushing through my socks, trying to escape the confines of my hiking boots.

  “What else?” Loki tapped his chin. “Oh, yes! Look!”

  He gestured past the hordes of shuffling zombies, sweeping his arm across the bay as if revealing a fabulous prize I’d just won. On the misty horizon, one of the glacial cliffs had begun to calve, sheeting massive curtains of ice into the water. The sound hit me half a second later: a muffled rumble like thunder through thick clouds.

  “Cool, huh?” Loki grinned. “The ice is melting much faster than I thought. I love global warming! We’ll be able to sail before the week is out, so really, you’re already too late. I’d turn around and go back to Valhalla if I were you. You’ve only got a few days to enjoy yourself before Ragnarok hits. Might as well take some of those fabulous yoga classes!”

  My rebellious fingernails reached the deck. They wove their way into the glistening gray surface, pulling me down, forcing me to double over. My toenails burst through the tips of my boots. They rooted me in place while dead men’s nails began to grow upward like saplings, curling eagerly around my shoelaces, vining their way up my ankles.

  Loki looked down at me with a gentle smile, as if watching a toddler take his first steps. “Yes, it’s a wonderful week for Doomsday. But if you do insist on challenging me”—he sighed and shook his head like You crazy kids and your quests—“then please leave my children out of it, will you? Poor Sam and Alex. They’ve suffered enough. If you care for them at all…Well, this quest will destroy them. I promise you that. They have no idea what they’ll be facing!”

  I fell to my knees. I could no longer tell where my own fingernails and toenails stopped and the ship began. Jagged branches of gray and black keratin tightened around my calves and wrists, chaining me to the deck, encircling my limbs, pulling me down into the fabric of the ship itself.

  “Take care, Magnus!” Loki called. “One way or another, we’ll talk again soon!”

  A rough hand clamped my shoulder, shaking me awake.

  “Magnus!” yelled Halfborn Gunderson. “Snap out of it, man! Grab an oar!”

  I found myself back on the deck of our bright yellow ship. We were drifting sideways through a cold, dense fog, the current pulling us to port, where the river fell away into roaring darkness.

  I swallowed the wet cement clogging my throat. “Is that another waterfall?”

  Mallory dropped onto the bench next to me. “One that’ll send us straight into Ginnungagap and kill us, yeah. You feel like rowing now?”

  T.J. and Halfborn took the bench in front of us. Together, we four rowed with all our strength, turning starboard and dragging our ship away from the precipice. My shoulders burned. My back muscles screamed in protest. Finally the roaring sound faded behind us. The fog burned away, and I saw that we were in Boston Harbor, not far from Old Ironsides. Rising on my left were the brick row houses and church steeples of Charlestown.

  T.J. turned and grinned. “See? That wasn’t so bad!”

  “Sure,” Mallory said. “Except for almost falling off the edge of the world and being vaporized.”

  Halfborn stretched his arms. “I feel like I’ve just carried an elephant up Bunker Hill, but good job, all….” He faltered when he saw my face. “Magnus? What is it?”

  I stared at my trembling hands. I felt as if my fingernails were still growing, trying to find their way back to the Ship of the Dead.

  “I had a little vision,” I muttered. “Give me a sec.”

  My friends exchanged wary looks. They all knew there was no such thing as a little vision.

  Mallory Keen scooted closer to me. “Gunderson, why don’t you take the rudder?”

  Halfborn frowned. “I don’t take orders from—”

  Mallory glared at him. Halfborn muttered under his breath and went to take the rudder.

  Mallory fixed me with her eyes, the green irises flecked with brown and orange like the shells of cardinals’ eggs. “Was it Loki you saw?”

  Normally, I didn’t get this close to Mallory unless she was pulling an ax out of my chest on the battlefield. She valued her personal space. There was something troubling about her gaze—a sort of free-floating anger, like a fire that jumped from rooftop to rooftop. You never knew what it would burn and what it would leave alone.

  “Yeah.” I described what I’d seen.

  Mallory’s lip curled with disgust. “That trickster…We’ve all been seeing him in our nightmares lately. When I get my hands on him—”

  “Hey, Mallory,” T.J. chided. “I know you want revenge even more than most of us, but—”

  Keen stopped him with a harsh look.