T hat evening, I dragged myself into the theater with my pushcart in tow. I’d just spent two hours under the boardwalk casting spindles for the boiler using nothing but beach sand, an apple crate, and a cheap blacksmithing kit from the general store. While I was at it, I melted down the dragon claws I’d purloined from the museum which earned me a copy of Morgan’s padlock key—and a chest full of concrete.

I thought about dropping off the pushcart and going home, until a soft splash coaxed me the rest of the way up the apron ramp.

Río was hovering off the floor looking like he was seriously reconsidering our arrangement. He drifted along next to me with the weightless grace of a silk scarf on a breeze while I trudged around the tank’s long viewing pane to leave the cart by the pump, climb the iron rungs, and slump down on my backside to wait.

He met me at the top, wavy lines of wet copper hair drawn over his cheeks. “You are here again.”

I cleared my throat enough to speak. “You’d prefer I wasn’t?”

He crossed his arms over his chest. “I did not think you would come given your professed aversion to conversation.”

“Good thing I ain’t here”—I sipped in a breath—“for conversation.”

Earlier, I had cooked un bacalao guisado to convert the culinary religions of everyone at the Albemarle, and had made sure to set some apart for Río in a jar. I pulled it out of my pocket and nearly fumbled it into the tank at the eyeful I got of his wet skin and swirling hair.

“I think I mentioned... salt cod’s better when you soak it,” I wheezed.

He leveled a mistrustful eye at the jar. “You mentioned.”

“This is the same stuff, just... soaked and cooked. Thought you might... like this better.”

I unscrewed the lid, then paused. I hadn’t thought through the business of sharing food so it wouldn’t dirty the water. Manners be damned, I took a piece of the cod in my fingers, got down on my stomach, and fit my arm through the lattice to offer it to him.

Río’s face was all damp suspicion. He plucked it away without touching my fingers, and though the piece was small enough to swallow whole, he nibbled off a corner and rolled it around his mouth like he’d bitten off a hunk of day-old queso blanco .

I licked the sauce off my fingers. “Well?”

He swallowed the microscopic bite and grimaced. “Merfolk do not adulterate our fish by cooking it.”

Bueno. I didn’t know what “adulterate” meant when it came to food, but it couldn’t be good.

“You did improve it, though,” he conceded, catching my disappointment.

“You don’t have to say—”

My voice snagged in my throat. Suddenly, and with no concern for dignity, a coughing fit muscled its way out of me. Below, Río watched with wide, startled eyes as I clambered back to sitting, and my useless lungs hawked air out instead of in.

“What in Neptune’s name is wrong with you, Benigno?”

I tossed my arm over my mouth to smother it. “It’ll pass. Just... dame un momento. ”

Río observed me sideways while I barked into my elbow, then ducked underwater. He began swimming in a wide, slow circle, and as I tried to catch my breath, he went around again, then a third time, until I got the powerful impression he was pacing .

Less than a minute later, he resurfaced. “Are you recovered now?”

I scowled. “Of course not.”

“I suppose the noxious air over your city has done this to you.”

“This ain’t my city,” I snorted, which spawned another fit. “ Carajo. I... I was probably just born this way.”

“ Born with traitorous lungs?” The concept shocked the snooty right out of his voice. “How can that be?”

“I dunno, it just is .”

“Have you been poisoned? How does it feel?”

“How does it feel ?” I gawped at him. “ Ave María , why would you ask me that?”

Río peered up at me with the tired impatience of a royal forced to mingle with commoners. “It interests me.”

This guy was a riot. No one had ever asked me what it was like to have asthma, and it especially defied description when I considered my audience. If Río couldn’t imagine being born this way, then he definitely couldn’t imagine the iron clamp around my ribs, the sense I’d inhaled something black and sticky that crowded out everything else in my chest, nor the bone-deep terror that somewhere a clock was marking the minutes before my lungs gave up breathing altogether and killed me instead.

How do you describe asthma to someone who can’t drown?

“It’s like thirst,” I rasped, finally. “Except instead of starving for water... it’s air.”

He shook his head, disturbed, which was an improvement over pitying me. “That sounds grave.”

I hacked. “It... it’s n-no picnic, that’s for damn sure.”

“What is a ‘nic’ that it must be picked?”

“No. I just mean”—I grasped at more air—“I don’t much enjoy it.”

Río laid back on the water, the liquid parting around his muscled chest. “Humans are such vulnerable creatures,” he mused, frowning. “I cannot understand how your fragile kind persists in blighting the globe with such rigor.”

“Well, we ain’t all perfect like you,” I sniped. “Most humans have good intentions... when we’re not stepping on each other’s heads just to stay alive.” My tetchiness hedged at the subtle change on Río’s face. “What?”

“You think I am perfect?”

“That’s not what... I mean...” I jabbed a warning finger at him. “Hey, stop mixing me up.”

A shadow crossed his face, then vanished. “Well, you should swim more,” he continued with the authority of a doctor. “That would help.”

“Can’t swim,” I muttered. “And anyhow, what makes you the expert?”

“I am mer,” he said, like that explained everything. “My lungs have four chambers compared to your two, half of which breathe water.”

“ Four chambers?” I gawped. “But how does your body just... know what to do?”

Río’s detached expression took on a mischievous hue. “I would invite you in for a demonstration,” he said smoothly, “but I fear you would not enjoy drowning.”

My scowl came back. I hadn’t cared when Río was just a bloodthirsty sea creature with haunting eyes and sandpaper palms, but now that he’d proven himself a busybody and a snob, wheezing in front of him felt no better than wheezing in front of Farty Walsh.

“You know what?” The words blew out of me with a whistle. “It’s time I got back to work.”

He sat up in the water, eyes scrunched in bafflement as they watched me hastily screw the lid back onto the jar and nearly drop it into the tank.

“You are embarrassed.”

“I’m tired.”

“You need not feel shame,” he said. “Who is to say what would happen to my lungs if I was out of water and had nothing but soiled air to breathe? This ailment is a part of you that you did not choose and cannot help.”

I got to my feet and teetered on the bars. “Easy for you to say, Mr. World’s-Best-Pair-of- Pulmones .” I headed for the ladder.

“It is the simple truth of every creature with a soul. You are not your body, Benigno.”

I froze in my step. When I turned back to snap at him, the look on Río’s face made me pause.

He was chewing his bottom lip, staring off like he was weighing the stakes of a gamble. A moment later, he looked up. “I can help you. If you will allow it.”

“Help me ? ?Por qué? ”

“Because you need it.”

Cristo. Between his liquid voice and the always-blue-ness of his eyes, he had a very inconvenient knack for making my ears burn. I stepped away from the ladder, not because of my ears, but because the biggest insult of having asthma was being desperate enough to do anything if it meant breathing properly. I sat back down.

“Sit taller,” he said like he was schooling me in table etiquette.

I tried.

“Good. Place one hand over your heart and another over your belly, but do not press in.”

Overlooking the fact that I didn’t generally touch people, myself included, I set my right hand on my chest, the other on my stomach. “All right,” I wheezed, “now what?”

“Listen closely. Make your throat thin, just a little, and breathe through your nose so it makes this sound...”

Río breathed deeply, his eyes fastened on mine as his chest expanded, except it was surprisingly loud, like drawing air through a vent. He took several breaths this way, his shoulders rising and rolling back in slow arcs, and as I listened, I realized I’d heard this sound before.

“That sounds just like the ocean,” I said.

He clicked his tongue impatiently. “Obviously. Now you try.”

I straightened up a bit more and drew a ragged breath in through my nose. It immediately caught in my throat. “I don’t—think—”

“You waste air by talking. Be quiet and try again.”

There are few things I hate more than being a novice, which might be why I didn’t clock out on Río’s challenge despite a lifetime of never getting my lungs to do a single thing I wanted them to do. It took several tries to make it work without coughing or closing up—but then, to my surprise, I started hearing it. A shish sound, like rolling tides.

“Well done.” His voice went suddenly low and calm. “Take in more. Enough to make both your hands rise up.”

I licked my lips, then drew the air in. My ribs resisted around it, hardening like sealant left to dry—

“ Relax , Benigno.”

“ I’m trying .”

“You called it thirst. Air surrounds you, yes?”

A cough escaped. “Y-yeah?”

“Then drink it in like water. Close your eyes.”

I closed them.

“See it in your mind. Touching every corner of your chest. The way a flame is doused in a rising tide,” he hummed. “It is cool... and calm...”

The eye of a hurricane is calm. Tití Luz was talking about surviving a war when she’d said it, but the metaphor felt apt as I wrestled for control of organs that resisted me like the Armada resisted McKinley. In my mind, I saw the storm, a rotating mass under my palm. I pulled in all the air I could...

There. A break in the clouds.

“You are doing well. Keep going.”

There had to be something to the siren lore after all. Río’s voice was deep. Musical. He kept reciting encouragement. I kept doing what he said.

Eventually, my mind started wandering. To Red Hook pier, stagnant, stinking, the color of café con leche . My next inhale swept the Gowanus clean as the jewel-toned waters of la Playa del Condado took its place. I imagined the surf rolling up to my ankles, erasing my footprints in the sand.

I felt a little dizzy. Also, my eyes were prickling, which didn’t make sense, because I’d long forgotten how to cry. It was as if all this breathing was thinning out the mesh of dirty gauze inside me, a moldy knot that had never touched air. I was breathing into it now. Felt it loosening, unwinding. Which roused a sensation I didn’t expect.

Fear.

That gnarled net was all that held my mutilated heart together. If it came undone—

“Open your eyes, Benigno.”

I opened them. I was swaying in my seat, my head so light, I nearly forgot where I was or what I was doing before I took a breath—the normal kind—and felt my eyes go wide.

The whistle was gone.

Río’s tail was treading the water so evenly he could have been standing with legs on solid ground. “Better?”

I inhaled again just to make sure. “Yeah,” I said in a gust of air. “What’d you do?”

He shrugged. “Nothing. You did that yourself, and you should do it more often if you do not want your lungs to betray you as much.”

My hand still lay over my heart. For a long moment, I rifled through my bilingual vocabulary for a word to describe the odd feeling under my fingers, but there wasn’t a precedent for it.

Río cleared his throat. “We should not speak any longer tonight. Your lungs need rest.”

“Right,” I whispered. “I’ll, uh, just finish up the pump then. Thanks for the breathing lesson.”

“Thank you as well. For el guisado .”

I puffed a short laugh. “You didn’t like it.”

“But it was kind of you,” he said, not laughing. “And kindness is its own food.”

His blue eyes, rimmed with golden lamplight, sent a current of warmth up my neck.

“De nada.”

Silently, I took my jar of bacalao back down the iron rungs and returned to my work.

Several hours and one completed circulation pump later, I gathered myself to go home and ventured a last look into the water where I expected to see Río sleeping. Instead, he was reclined against the wall, arms folded, silent and watching.

I waved goodbye. He didn’t. But there was something in the tilt of his head, in the thoughtful set of his mouth I hadn’t seen before. Whether he liked my company or just didn’t want to be alone again, he seemed a little sorry to see me go.

I probably imagined it.