Halfway through the night, you wake up thrashing, completely soaked in your bedclothes. The thrashing and splashing wake me up too. In the moonlight streaming in through the window, I see your half of the bed has turned into the sea. That’s when I’m scared that you’ll lose sight of me, lose your moorings. That’s when I’m scared you’ll swim away.

Even after this midnight madness, you rush into the kitchen, clothes and skin and long hair dripping, trailing so many streams on the floor. You grab small fish out of the bowl I had bought you and devour them raw with your fingers. You look hungry, panicked, trapped. You don’t want me to hold you. I think you’re crying. I think in your language you’re crying, though the low, guttural cadence that soars from your throat sounds like surf song to me.

You can see the sea from our flat, but it’s down nine floors of building, across a busy highway and beyond a dull strip of beach mostly littered with plastic bags and empty food wrappers. The kitchen window gets the widest view. Is that why you spend so much time in the kitchen?

Mumbai is teeming with sea fauna. Half the city is reclaimed from the sea anyway. Some of the sea folk live on the edges of the urban sprawl, hunting for lesser sea fauna and sending them, by the truckload, to the bazaars and kitchens of the city. Many of them sell peanuts, balloons or candy floss to children and romancing couples who flock the beaches in Juhu and Chowpatty. But it could also be the autowalla in the street. It could be the guy furiously writing programs in a cubicle somewhere, assiduously keeping the sea from his heart.

And then there is you, thrashing and struggling to breathe in our little flat open to the sea.

On the second morning, I take the day off work to visit my parents. In the old house, when I find myself alone with my mother, I ask her what I should do. Mama just shakes her head.

“They always try to leave, don’t they? If you were a man, I’d have told you to give her a baby.” She turns away from me to stir whatever she’s cooking. “That’s how I held on to your papa.”

This is a revelation. I think of my father – round-shouldered, timid, balding – as he snores gently on the cane chair out in the courtyard, newspaper balanced on his stomach. I love Papa, but I fail to imagine him as some kind of dashing philanderer. Papa has always been this small, sincere man who worked hard at the bank, devoted to his wife and daughter. To think of him as anything besides makes my head reel.

Besides, we cannot have a baby. Not now, probably not ever. I have no patience for babies. And you – you’re so wild, strange, free. I cannot think of you changing nappies or waiting in front of the kindergarten in the afternoon heat, tired and bored and gossipy like the other women. You’re too ethereal, too precious to be worn down to something like that.

I turn next to Sanjoy, the only college friend I have kept over the years. I adore Sanjoy, though he can be ridiculously shallow sometimes. The first time I mentioned you to him, he had wrinkled his nose and said, “But aren’t those sea types a bit too...fishy? Like, slimy? Y’know...like octopi?”

“Octopuses,” I had coldly replied. “And octopuses aren’t fish. Neither is Matsa.”

“Does this mean you’re off all seafood now?” Sanjoy had quipped, cheerfully spearing a wedge of sushi with his fork.

I’d picked up a strip of fried chicken from my plate and pointedly chewed the flesh off the bone. “I don’t see how eating land food has alienated me from you.”

Sanjoy’s pearl of wisdom on the situation turns out to be this: “Darling, just buy a big aquarium and stick her in it, why don’t you?”

“Stick my girlfriend...in an aquarium? Thank you very much, but no.”

Besides, I explain to him, the need is not to fix you a simulated environment that will give you the delusion of the sea. The need is to break your obsession, to gently ease you into the land life you and I are trying to build together. That’s what you want too, don’t you? You want to stay here with me. You want the midnight madness to stop.

I suspect the guy who brings me my lunch dabba at office is sea fauna, but he never gives me the time of day. He only makes conversation with women if they’re pretty. He sometimes tries to chat up the receptionist, who is skinny, stylish and waves him away all the time. I know this type of man – handsome, sharp-featured, who comes to the city with dreams of breaking into Bollywood but then sticks around working as a waiter, cleaner and lunchbox deliveryman. He looks at my spiked hair and rounded arms with a kind of haughty disapproval. Must’ve been a dolphin back at home, I hostilely think.

After we struggle every night for a month, I decide to let you go. “Matsa,” I tell you, “tonight’s a full-moon night. I will drive you down to Colaba Point at midnight, and then you can go home.”

You nod, but your large, dark eyes refuse to meet mine. You refuse to confront the heartbreak in my voice, which I unsuccessfully try to hide. We are standing in the kitchen. It is daytime and you look almost normal, almost happily settled, your little curls ruffling in the salty breeze that gushes in from the wide kitchen window. But we both know you’re not. The sea will always haunt your dreams. You will always wake up in the depths of them, swimming, thrashing, fighting for the rush of water in your gills. There’s no point carrying on with this forced assimilation.

Later, I drive you down. I park and we both get out of the car, step across the concrete ledge and on to the beach. There is no one else around apart from the cars whizzing past at high speed. A lonely drunk lies upon a ledge in a distance and sings at the sky. Wavering notes of longing and desolation drift over the dark waters and are lost.

I wish I could sing to you. I say, “Give my regards to your folks. Tell them I tried my best.”

You step out of your pumps and stand gingerly upon the sand. You slip your dress off your shoulders. (In the moonlight your body is dark and fluid. I want to clutch you in my arms and lead you back home. I turn my eyes, blinking away moisture.) Lastly, you prise open my palm and gently place the carved silver ring I had given you when we first fell in love. Nothing made on land is welcome in the sea.

I drop the ring into my breast pocket and drive back home. The flat is cold, silent – incomplete without you. I go into the kitchen and shut the window. The hinges protest noisily. In the half year that we lived in this flat, the kitchen window has always been open, through rain and sun and even the occasional dust storm that blinded us and covered every surface with a film of fine sand. You’ve always wanted the sea wind to surround you. Now I want the sea out.

I go into the bedroom, drop my trousers on the floor and switch off the light. For the first time in the month, I may perhaps sleep in peace.

Halfway through the night, I wake up startled to the sound of waves crashing on to my bed. I turn to the space next to me...and in the light of the full moon, I see your half of the bed has turned into the sea. The silvery water stretches all the way to the horizon, rippling, dancing, but in that vast, empty stretch, there is not a sign of you. I lie curled up by the seaside and weep.

The Gollancz Book of South Asian Science Fiction

Excerpted with permission from “The Sea Sings at Night”, by Mimi Mondal, from The Gollancz Book of South Asian Science Fiction, edited by Tarun K Saint, Hachette.