Olivia shrugged. “Safety and accessibility were handled by different teams. That’s not unusual. A project this size, you’re always going to have contradictions, because no one has the time to ask whether every little thing made sense.”

  “So I climb up to find the captain, and then what?” asked Luis. “He produces a squadron of trained marines with flamethrowers?”

  “All the marines are already patrolling the ship, which means most of them are probably already dead, and you’re not going,” said Olivia. “I am.”

  Silence fell, broken by the soft whirr of Jillian’s machines, which continued chugging away, turning samples into science, extracting results from ruin. Holly never stopped her work. She was tireless, maybe because science didn’t care if she could hear it; she had a common language with the machines, and that could never be taken away.

  Tory found her voice first. “What?” she said. “No. You’re not … No.”

  “I am,” said Olivia. “I’m smaller than you are. I have the narrowest shoulders. I work out every day. If you’re going to dress like Emma Frost on national webcasts, you need to have the body for it. I know how to free-climb. I can make it up the shaft, and besides, I’m the nonscientist. If someone is going to find a better solution, it’s not going to be me. This is the thing I can do.”

  “And when you die?” asked Tory. “What am I supposed to do then?”

  “I fell in love for the first time at a convention,” said Olivia. “Her name was Jennie, but everyone called her Otter, and she kissed like there was some sort of time limit on the idea of kissing. I met her on Friday; I fell into bed with her on Saturday; I missed two broadcasts because I was in bed with her all day Sunday. Um.” Her cheeks flared red as she realized who was in the room. “Mr. Blackwell, I—”

  “Don’t worry about it,” he said. “I think you’ve earned a little forgiveness. I’m not going to tell on you.”

  “Thank you,” she whispered, before saying, “We had to check out Monday. I went to my room to pack my things, and when I came looking for her, she was gone. She didn’t leave a note. I didn’t know her number or her preferred online handle or even her last name. I never saw her again. I fell in love and got my heart broken on the same weekend, because conventions are this weird liminal space that isn’t real and isn’t false and doesn’t count when the banners come down.”

  “Why are you telling me this?” asked Tory.

  “Because this mission is like a big convention, or a reality show. It’s a pressure cooker. They put us all in one space, and we can’t get away, and everything happens so fast. It happens so fast.” She smiled sadly at Tory. “If I don’t come back, you’ll keep going. That’s what you’ll do. I haven’t been here long enough for you to do anything else. Eventually, maybe, I’ll have been here long enough. If I come back, we can try for that. But right now, I’m the one who makes sense. So I’m the one who’s going.”

  “She’s right,” said Jillian. “Mr. Martines is wounded. Theo can’t climb, I won’t fit, and in addition to her other advantages, Miss Sanderson is familiar with the space, which makes her chances of success higher than Miss Stewart’s. Miss Sanderson is our best candidate.”

  “You didn’t mention Holly,” said Tory.

  “Dr. Wilson is acting as my assistant. Even if I were a candidate, she wouldn’t be. We need to understand what these creatures do when they bite or otherwise infect one of us, or we’ll have no hope of saving anyone whose system is compromised. We’re fighting a battle on multiple fronts, Miss Stewart, and while it would be nice to pretend it was fair, it simply isn’t.”

  “How far to the nearest hatch?” asked Theo.

  Silence fell again, lasting for only a few moments before Olivia said, “It should be about twenty feet from here. Inside the hall.”

  “Can you make it that far by yourself?”

  Olivia paled. It was obvious, just from looking at her expression, that she hadn’t considered that aspect of her plan. “I guess I have to,” she said.

  “No, you don’t,” said Tory. “Luis, give me your flamethrower.”

  “It’s not a flamethrower,” he protested, even as he was handing it to her. “It’s a blowtorch, and not a very powerful one. It’s hot, but it doesn’t have much range.”

  “I don’t care. Liv needs the tranq gun,” said Tory. “I’ll walk you to the hatch, Liv. From there you’re on your own.”

  “How will you get back?” asked Olivia.

  Tory offered a wry smile. “Blowtorch.”

  It was an imperfect solution. It was probably going to get one or both of them killed. There wasn’t anything better.

  “I don’t think we should let you go,” said Luis. “If Olivia can’t make it to the hatch by herself, she’s never going to make it to the top of the ship.”

  Olivia bristled, but it was Tory who spoke. “No one’s letting me do anything,” she said. “I’m going with her because it makes the most sense.”

  “God save me from the children,” muttered Jillian. “We’re done fighting. We’re only doing it because some of you have managed to latch on to the delusional idea that we’re safe in here just because this room has a door and a lock. We’re not safe. We’re not going to be safe until we finish getting the damn shutters deployed.” Even then, they wouldn’t be safe, not until they were miles from here, with their feet back on solid ground. That part didn’t need to be said. That part was obvious to all of them.

  “So we go?” asked Tory.

  “You go,” said Jillian. “Miss Sanderson?”

  “I’m ready,” said Olivia, as bravely as she could—and really, her voice was surprisingly steady. She stood up straight, squaring her shoulders, and even flashed the room a pale ghost of her usual camera-ready smile. “Let’s do this.”

  Tory walked to the door, unlocking it and creaking it open a few inches, the blowtorch in her hand, ready to be shoved into the face of anything that might lunge at them out of the darkness. Nothing moved on the deck outside the lab. She opened the door farther, tense, waiting for the moment when all hell broke loose.

  Hell seemed content to stay bound, at least for the moment. The deck was motionless. Tory eased herself out the door, motioning for Olivia to follow. Someone—Dr. Toth, probably; Luis and Mr. Blackwell couldn’t walk, and Holly’s hands were full—closed the door once Olivia was out. There was a click as the bolt slid home. Tory realized, with a sickening lurch, that they hadn’t agreed on a secret knock or passcode; when she came back and tried to get inside, they might think she was a siren and leave her where she was.

  That was something to worry about later. Right now she needed to get Olivia to her destination. She turned to the other woman, mouthing, “Which way?”

  Olivia pointed. Tory nodded, and they started down the deck. Neither was in the lead; Tory had the weapon but Olivia had the information, and so they walked side by side, slow, careful, setting their feet down as gently as they could. Avoiding the slime was impossible. They had to pause several times, one of them providing a stable arm for the other while they walked, one by one, through the sticky trails. Getting back was going to be an adventure … and that, too, was something to worry about later.

  Dimly, Tory realized that she was already starting to write herself off. The situation was too dire: there was too much blood. She wasn’t going to survive. Maybe none of them were. No matter what happened, the Melusine couldn’t be allowed to go the way of the Atargatis; she couldn’t be lost with all hands and no clear narrative of events. The world had to know. Lowering the shutters would help with that. Even if every person on the ship wound up ripped to shreds, the sirens would be trapped. They hadn’t shown any real inclination toward destruction for destruction’s sake. The computers and lab samples and everything else would be intact when the rescue crews came. Too late to save the people, maybe, but not too late to save the science.

  Not too late to save the science.

  Olivia stopped at a rectangular depression
in the ship’s wall. It was recessed by roughly three inches, creating space for the small keypad that was set into the side. It was small and subtle and Tory had walked past it and others like it dozens of times without realizing anything was different.

  “This is it,” mouthed Olivia, pointing to the rectangle.

  Tory nodded understanding, leaned in, and kissed her.

  It was a brief, glancing kiss; anything deeper or more involved would have risked both their lives. That wasn’t the goal. They might die here, but they weren’t going to do it yet. Olivia’s eyes widened in brief surprise before she leaned closer and kissed Tory back, putting as much as she dared into the gesture. It was a moment of peace stolen from the jaws of chaos, and it meant more than either of them could say.

  They pulled back. The moment passed. Olivia offered a quick, half-shy smile before she turned to the keypad and punched in the code. There was a soft beep. A piece of wall, two feet by two feet, slid to the side, revealing the chute on the other side.

  The ship’s architects had anticipated the need for maintenance. Handgrips studded the wall, spaced like rungs, moving up and down through the clean white tunnel. There were no lights, Tory realized; once Olivia was in there, she would be moving through total darkness.

  “It’s okay,” mouthed Olivia, and bent to climb inside. The keypad beeped again. The hatch slid shut, and Tory was alone.

  Behind her, something hissed.

  The inside of the tube was tight. It had been tight the first time she’d climbed inside, back when she and Ray were exploring the ship (don’t think about Ray don’t think about Ray, and it didn’t matter how much she scolded herself, because she couldn’t stop), but that had been a quick in-and-out. Open the hatch, climb in, get comfortable hanging suspended in the black, isolated space, push the hatch, climb out. It hadn’t been a prolonged isolation in absolute darkness. It hadn’t been her, and just her, climbing through the body of the Melusine, putting one hand over the other, waiting for the sound of snarls to echo from above and tell her she’d been wrong, the space had been compromised after all.

  Olivia Sanderson climbed through the dark, and waited for her death to find her.

  She missed her camera. It had been a reassuring talisman against reality. As long as she was watching it through the camera, it wasn’t real. But there was no way to carry a camera while she was climbing through the dark, and if she’d hung it around her neck, it would have knocked against the sides of the tube, echoing and attracting attention. The tranquilizer gun was bad enough, shoved into her waistband and rubbing against her skin.

  She was moving through atrocities. She knew that. Outside her safe little tube there were monsters and murders and terrible things, and if she stopped to open any given hatch, she would be rolling the dice on her own survival. One thing they hadn’t talked about back in the lab (which already felt so far away, like something out of a dream): when she reached the top, when she opened the hatch and slipped into the light, what was she going to find? It might be safety. It might be the captain and his men, holding the line against the monsters from below. Or it might be a slaughter. She could stick her head out and have it removed in the same terrible moment, her body falling to land on whatever laundry or debris had been allowed to build up in the belly of the ship.

  There hadn’t been any other way. There hadn’t been any other choice. If she wanted a chance to save her friends—to save herself—she had to do this. Besides, it was nice to be the hero for a change. She was Mario, climbing through the pipes to save the Mushroom Kingdom, instead of Peach, getting kidnapped by monster turtles. She was April O’Neil, traveling through the sewers to rescue her beloved Ninja Turtles. She was … she was …

  She was scared out of her mind. This wasn’t what she’d signed up for. All she’d ever wanted was the chance to show the world who she was and what she could do, to make them understand that she was more than a collection of traits randomly generated by some cosmic lottery. She was a person. She could be a hero if she wanted to. She could save the world, she could change the world, she could belong in the world, and anyone who wanted to say she couldn’t could learn to live with how wrong they were.

  But she hadn’t wanted to die. That had never been part of the plan. Do a couple of years with Imagine, build a fan base, build a brand, and then head out into the wider world, see if she couldn’t get a job emceeing a reality show or playing host for a children’s science program. Change the world by living in it, not by dying for it.

  It was really a shame the way nothing ever seemed to want to go according to plan. Hand over hand, Olivia kept climbing, moving toward the inevitable future.

  Tory turned.

  The siren was a small one, as the specimens she’d seen went: it was about the size of a scrawny thirteen-year-old, holding itself rigidly up on its arms. It was hissing, but it looked as startled to see her as she was to see it. She could easily imagine the adults sending it to double-check an area they were reasonably sure had already been denuded of prey, getting the obnoxious kid out of the way.

  (And that was a dangerously anthropomorphic way of looking at things, because this wasn’t a child, innocent and trusting and looking for a friend. This wasn’t a fairy tale come to life. This was a dangerous animal, intelligent or not, and it would kill her if she gave it half a chance. It was her job not to let it.)

  It was too far away to be dissuaded by her blowtorch, assuming it would even realize what the odd, flickering light was. None of the sirens had shown any sign of understanding fire before it was on them, consuming their flesh and introducing them to a new flavor of suffering. She could have waved the torch at a lion or bear to scare it away. With the siren she was reduced to a tactic that had worked for humans since the dawn of recorded time: she turned, and she ran.

  Hissing wildly, the siren pursued.

  Tory ran as fast as her feet would carry her, watching for an open, undamaged door, for a hallway, for anything that might get her away from the monster rapidly closing the distance between them. She knew the ship hadn’t rearranged itself to spite her, but it felt that way as yard after yard of deck unspooled without providing any answers.

  She was so focused on where she was going that she wasn’t paying attention to where she was putting her feet. Her heel came down, hard, on a deep patch of slime, and she found herself skidding suddenly out of control. She waved her arms frantically, trying to stop herself, but it was too late. She slammed into the rail, arms still flailing, and went over the side before she could get her momentum under control.

  I’m going to die, she thought frantically, and tried to force her body into a proper diving stance, arms out, legs together, head bent at a protective angle. It was the only thing left that she could do.

  She dropped along the length of the Melusine, hit the water, and was gone.

  ZONE SIX: DEMERSAL

  The truth is out there. And when we find it, I’m pretty sure we’re going to want it to stay out there, while the rest of us go home to our beds.

  —Luis Martines

  The trouble with discovery is that it goes two ways. For you to find something, that thing must also find you.

  —Victoria Stewart

  Heather’s gone and Hallie’s God-knows-where, and for the first time in my life, I’m alone. I used to say I wanted this, when I was a kid and one or both of my sisters was getting more attention than I thought they deserved. I hated Heather for having my face and my hands and using them to do things I didn’t approve of. It was like having my own personal Imp of the Perverse, constantly devoted to damaging my reputation. I got to know what I looked like with skinned knees and black eyes—and since neither of us could hear, and most hearing adults couldn’t tell us apart, the only way I didn’t get in trouble right alongside her was by staying so spotless that there was no possible way I could have done anything wrong. She rendered me sterile, clinical, all because I was looking for contrast.

  Hallie, though … Hallie could hear.
Hallie was the first and the eldest, and she was the one who’d had our parents’ full attention, and I was so jealous of her that it burned. No one ever mistook me for her. Sometimes I wished they would.

  And they’re both gone, and I wish I could find my eight-year-old self and tell her to be careful what she wishes for, because the universe is listening, and someday, no matter how many times she changes her mind, she just might get it.

  —From the diary of Dr. Holly Wilson, September 2, 2022

  Science is not a matter of belief. Science does not care whether you believe in it or not. Science will continue to do what science will do, free from morality, free from ethical concerns, and most of all, free from the petty worry that it will not be believed. Belief has shaped the history of human accomplishment—we believe we can, and so we do—but belief has never changed the natural world. The mountain does not vanish because we believe it should. The unicorn does not appear because we believe it will.

  The mermaid does not care whether or not we believe in its existence. Somewhere far from here, the mermaid continues to do what it has always done: it continues to thrive. And it waits for us to realize that belief is, in the end, irrelevant.

  —Transcript from the lecture “Mermaids: Myth or Monster,” given by Dr. Jillian Toth

  CHAPTER 33

  Western Pacific Ocean, above the Mariana Trench: September 3, 2022

  Momentum drove Tory at least ten feet down. The salt water stung her eyes, and she blinked rapidly, trying to acclimatize to her surroundings before she became too disoriented to remember which way was up. In a swimming pool, going limp and allowing herself to float to the surface might have worked, but the sea was not some tame backyard amusement, meant to coddle children as they learned the ways of the water. The sea was a jungle of currents and undertows, and the water moved. If she didn’t fight to find her way back to the air, she never would.