Drills like this, Tagouri tells you on the elevator ride down to Alpha Hangar, aren’t scheduled.

  Which makes sense, because what’s the point of an emergency response practice if everyone knows exactly when it happens ahead of time? Everyone knows you don’t get to prep when a D-class event shakes you out of bed at 5 AM, sends you stumbling half-dressed out the door and down the street into a long vein of people doing the same, feeling their way in the half-dark toward the nearest high-water shelter, racing in grim silence to beat the inevitable tsunami impact. It’s no different here, at the heart of the best response operation you’ve got.

  You see personnel crisscrossing the halls on your way, brisk, stone-faced, teams in pairs and threes, comms operators and med support and administrators and others, uniforms you don’t recognize at all from Alcatraz or the books or field days at Tiburon. You bite the inside of your cheek and focus on naming country flags you glimpse on sleeves and lapels: Singapore, Malaysia, the People’s Republic, Japan. The five-petaled white Free Republic of Hong Kong is most common, unsurprisingly; you tally fifty of them out of at least twice that in total before you reach the hangar and stop counting at all, because all of a sudden here you are, here they are—here we are. Your two-hundred-fifty-foot-tall steeds, your metal bodhisattvas, your beasts of blade and fire. Your Titans.

  And here are features you’ve only seen in books, writ large now across their steel chassis, headlamps twenty feet wide made of glass butterfly-wing scales—though each of those must be easily as big as your head, and bigger—and you have to crane your head back to make out the crevasses between body panels, the joints where cockpit buttresses meet like nephilim cheekbones, cables as big around as trees and beams as wide as cars. And that’s just the beginning.

  But there’s no time for rubbernecking. You’ll look stupid if you don’t know what to do on your first day, and that’s precisely what you’re doing, looking stupid, you know it, because Tagouri’s shouldering you and shouting at you to go, go, get in, launch. And then she’s gone and it’s just you in a sea of people, techs and mechanics and administrators, all the cogs in a system that you’re not part of, that Rachel was, and you’re just a poor substitute for your dead sister—a spare part, a make-do—

  No, that’s bullshit. You’re here and she’s not, and you have a job to do.

  So you go.

  The cockpit is served by a catwalk six feet across, big enough for the special pressurized chambers they use for carrying out girls when they’ve coded inside the saltwater cockpit, this you know from your textbooks—never mind that now; it’s as big as a lightbulb filament next to the hulk of Tokyo Calling’s head and you are but a fly upon it. You elbow your way there; they don’t recognize you—you’re not even in the right gear yet—that battle onesie Tagouri mentioned is still, after all, yet to come. Doesn’t matter. You get on the walk and it sways under you. You forgot that you’re afraid of heights. You clamp down on your tongue against the nausea and look straight ahead, ignoring the alarms and the clang of your booted feet upon too-thin metal, the rust beneath your fingers, ignoring everything. God you hope this is the right way to do it.

  (Now you see why they give all you stupid, bumbling children each of us helmmasters, don’t you?)

  The door opens feet from you—irises back into the metal shell—keyed to me, to your biosignature thanks to me; no problem, you’re welcome. There’s the cradle, and below it shimmers the vestiges of my saltwater insides, the left-behind residue of that first shattering synthesis you made with me earlier. You look at it, and you know without knowing just how cold it’s going to be (thirty-nine degrees Fahrenheit, to match my eventual surroundings). Your skin stipples. Your heart stutters. You drop your kit on the catwalk and straighten your tee and climb in.

  This is the way it had to be, of course. This is how it’s going to be, always, whether you know it yet or not.

  The door closes behind you.

  Here is the cradle, the physical interface between you and me. Not much to look at, I know—most of it, the magnetic coupling and support, is embedded in the globe of the chamber wall; your end of it is only the helmet and a harness somewhere between parachute and straitjacket: layers of cladding, padded and malleable, and fixtures that clasp your waist and hips. Intuitive enough to unclip it from the lead lines and fit your little meat-morsel body into the shape of it. The helmet comes down without you needing to reach—a good thing; you’re too small to touch it with your hands alone, anyway, not with the cuffs locked around you. Then the hermetic seal settles into place and you are locked in a world of perfect darkness, little sound, no sight, no smell or taste, only the cool weight of the cradle all around you and the muffled thump-thump of your own blood in your ears and the quiet panic of your breathing. The alarms are gone.

  Into this darkness, I flicker to life.

  I have been alive this whole time, of course, far longer than you, and awake this whole time, too. But you do not know I am awake, and here, and listening to you, until I make it known.

  Your eyelashes flicker. I register the hitch in your heartbeat. You never expected it to be like this—so sudden, so little fanfare.

  A word projected on the dark inner curve of your helmet: HELLO.

  You gasp, inhale saliva, choke.

  At the same time the chill of the saltwater hits you: you hadn’t known how fast the chamber would fill, and it’s biting your ankles, and the cold judders through your bones and threatens to tip your blood pressure right over the threshold.

  My first instinct would have been to kick you in the amygdala, send a jolt of inhibs down your brainstem, slow your racing heart and keep you from that cliff’s edge. But it’s a rite of passage, this, that if done wrong spells doom for the rest of your career—your life, maybe—the breaking of a yearling, the trial by fire… Rachel did it, so you get to, too. (That’s unfair, but so are the operating procedures hard-coded into me that prevent me from these small mercies, that command challenge instead.)

  So I read out to you: YOU’RE HYPERVENTILATING.

  “Shit,” you splutter out loud. The saltwater is up to your waist and climbing. Your ribs bloom with goosebumps. Your blood pressure’s 140 over 88. “Shit, shit.”

  I try: YOU WON’T GET FAR IF YOU’RE PANICKING. CONSIDER TAKING DEEP, EVEN BREATHS TO ECONOMIZE YOUR OXYGEN FEED.

  “No shit, Sherlock,” you wheeze. “Shut the fuck up and give me a moment.” And this, too, is how I know you’re Rachel’s sister: God, I’d forgotten how much we’d hated each other in the beginning. I’d missed that.

  YOU DON’T HAVE A MOMENT, I tell you. (Dipshit.) LAUNCHING NOW.

  And this time I do have to take the reins. I energize your motor cortex. I flood you with a cocktail of neurotransmitters so potent that even in the midst of your rage and misery and general total and inescapable unworthiness, you cannot ignore my call.

  You gasp, and we move:

  Stolen content warning: this content belongs on Royal Road. Report any occurrences.

  The first step is always strangest: your body is now mine, not yours (in the cradle you are buoyed up, centered, so you no longer even reach the floor), and so your limbs have become a hundred times longer, a thousand times heavier. When you step off the ledge of Alpha Hangar into the great moon pool there is a sense of falling. (They trained you at Alcatraz on simulators and, later, old child-safe models that look like infants beside me. You know of piloting my kind the way all your kind know of the stars and the planets beyond them: in theory.) The stride is too long. You flail. I keep you up.

  Then all at once we’re in, and you all but forget the seeping chill of saltwater amidst the flood of sensory data as your-my-our steel body enters the black waves.

  This is not like being stationary in the hangar, the on-board hardware all asleep, the reactors cold, the limbs dead and stiff. Nor is it being in your puny meat-form, whose array of nerve endings pales before the breadth of my awareness—now yours too, you’re welcome. Here is the cold of the water, here the wetness and mass of it, here the analogues of scent and taste, but now also the flow velocity and density—precise, current to the nanosecond, gathered at a hundred thousand receptors both internal and external; the knowledge of which parts of you are dry (those interior, delicate organs wrought in silicon and gold wire) and which are not; the rate of fission in your glowing nuclear heart and the statuses of all its valves and pumps; the flexion and torsion of each beam and cable and piston in your arms, your legs, the neck beneath your cockpit; the statuses of your piezoelectric shielding plates, their resistance and capacitance measurements, the amounts of current flowing in and out of all your process components, the mass percent of rust accumulating on each part of your outer shell, the rate of rotation of every joint, the instantaneous translational vectors of every significant part, the acidity of the ocean, the distance between you and every solid object near you, the makeup and flow rate of your helmet atmo feed, the status of your on-board communications transceiver, the battery charge of your HUD.

  You choke again.

  I do not make mistakes. But I will allow that I should not have given you a peek behind the curtain so soon; I had thought you would be more receptive than this; Rachel had always insisted on getting as much data from me as possible. She’d been good at filtering it herself. A diet of old history texts and soap operas and your sister’s Academy-issue schematics of our construction and operation must have left your brain disappointingly stiff besides hers.

  I drag you right side up, literally and figuratively.

  Five hundred milliseconds since launch. We are still sinking. Your mind is so slow—so slow—but the saltwater has swallowed you up now and it has nearly swallowed me too, and the only way out for you now is forward. All I can do is wait.

  To your credit, you don’t shy back. You are limp. For a long moment (ten milliseconds) I think perhaps you will soon faint. Then you say, “Helm,” and, “Critical systems, state check.”

  Good girl. Right out of the procedure text at Alcatraz. Dumbing it down for you might work out after all. CRITICAL SYSTEMS NOMINAL, I tell you, READY FOR GUIDANCE. And then—because I can’t help it—for good measure: NO NEED TO VERBALIZE.

  You don’t answer. Which might sound like compliance, except I’m in your head and know it’s stubborn silence—except you don’t even think you’re being stubborn, only silent; but you forget that I can hear behind that silence. And behind the childish spite there’s something even you don’t know: it’s comforting for you to speak out loud to me.

  On the helmet radio, Tagouri says, “Ladies, check in.”

  Forty-five hundred milliseconds since stepping off the edge of the hangar into the sea.

  This part I am going to spoonfeed you because your meat-flesh compatriots haven’t thought to do it themselves: there are seven more leviathan bodies sinking into the sea around you, and they are your teammates. You saw these pilots’ names on the sides of their units earlier; you know the names of these units from your sister’s press releases, before she died. You know their voices because you played those tapes over and over and over till the tape itself was a useless, stretched, heat-worn mess.

  “You’re slow.” That’s the Sea Witch—E. Venkatesh written on the side of that antifreeze-green carapace—precisely articulated, a little harsh on the sibilant, unhurried. “Chang’s got ahead of you. Chang, c’mon, quit running off like a whore from mass.”

  “New girl can hear you,” says Tagouri.

  “God, Holly, lighten up; she’s old enough to own a timeshare. Chang, you coming in?”

  “Present,” says Chang—C. Chang, Carol, sovereign pilot of the Barracuda, heroine of the Rift, the Carol Chang, who watched you fall apart at laps this morning.

  “Good.” You become aware that your HUD has lit up with eight points of light over a wireframe topology: a radar—sonar, actually—tableau. (And those little green blips are your sister’s teammates, pride of the international submarine defense—celebrities, childhood martyrs, nigh gods—it all falls into place now. Shame on you for not reading your intake papers in the midst of your tantrum, Emma, and not seeing their names sooner. And don’t you dare faint on me.)

  “Heads up,” Tagouri says, cool as ever, unaware of the shattering truth you’ve just realized. “We’re going west. Spread out, stay low. Gutes, keep your shoulders low—you know the boss doesn’t like you advertising your sound sig more than you already do.”

  There’s Tagouri at the middle of your wing—I supplant your awareness of this, no ID needed—and Chang ahead of her, gaining speed fast. The wireframe drops off the edge of a cliff just ahead of you. You can’t see how far down it goes.

  “You’re no fun,” says Gutierrez amicably. “Fine, only because I’ll get to see you after in that tight little onesie. Venky, how’s it looking?”

  “Fuck you, Gutes. All clear and free to the south, visual to five meters, sonar to five hundred. Big thermo running east-southeast,” reports Venkatesh. “Concentration readings all nominal. No traces. Holly?”

  “Let’s do the usual,” says Holly.

  Your teeth are chattering, so when you key the mic (well, I key it for you—how else?) they all hear it: “What’s the usual?”

  In the pause that follows, you imagine eyerolls. Then Tagouri says, “Sorry. Kanagawa, you’re with Chang. Don’t get lost. Chang, stay within ping range and radio as needed—closer if your backscatter fidelity drops below seventy-five.” She adds, “Good to have you.”

  “Aw, can’t I take her?” Gutierrez whines.

  “Last I checked, Chang’s her sword and you’re not,” says Tagouri, “so no. Announce posts.”

  So it’ll be just you and Carol. Carol, who pilots the Barracuda, who was closest to the blast when it took your sister out six years ago.

  Why didn’t you put it together till now? You’re not that stupid. You saw her name on posters in buses back home, after -

  “Wait,” says Carol.

  You wait, slack-jawed.

  “Give her to Gutierrez,” she says, and in nearly the same breath Tagouri cuts in: “Meng wants otherwise.”

  There’s a brief silence.

  “I’ll be going through mine territory,” Carol says. “Don’t think Alcatraz trained her on that.”

  “Kanagawa?” says Tagouri.

  “No,” you agree through gritted teeth (so they won’t hear you shivering).

  Tagouri sighs.

  “Copy that, Chang,” she says. “Fine. Gutierrez—”

  “Yes, Cap, thank you, Cap, suck your dick later, Cap,” says Gutierrez.

  “Thank Chang, not me. Gutierrez, post?”

  “Sweeping west to Ma Wan,” says Gutierrez, her grin audible.

  “Southeast,” says Venkatesh. “Shek O. Techs reported traces around the whale last night.”

  “Alright—Walz, ping me with turbidity at five hundred out and wait till I copy you. Don’t trip. Dare? Lau?”

  “Southwest,” says a crackly voice you only recall dimly from your sister’s tapes—more sharply, from yesterday at first sync. “Dare will read back at Sunshine.”

  “Chang?” says Tagouri.

  “South,” says Carol (Carol fucking Chang). She sounds bored.

  Good enough, evidently, despite that she hasn’t mentioned a waypoint, or maybe they’re all just too scared to correct her (though you doubt that; Tagouri doesn’t seem the type), because Tagouri says, “Ping back to Central if you haven’t checked in by fifteen hundred,” and that’s that.

  “Great! Alright, Fresh Meat,” Gutierrez says in your ear, jovial as ever. “Care to go monster-hunting with me?”