There were things about Milo I’d stopped noticing years ago.

The way his hands were always cool, even in the middle of a Port Jarrah summer, so that I’d press my sunburnt cheek to his palm and sigh. The way he never seemed to eat. He’d sit across from me while I demolished a pad thai, sipping water and stealing exactly one peanut. The way the bathroom was always damp — not steamy, just wet, every surface beaded with moisture, even when no one had showered for hours.

The way he kept the bathroom door shut. Not just when he was in there — always, every hour of the day, as if something might escape. If I left it open after my shower, I’d come back ten minutes later to find it quietly closed again.

I’d noticed all of it, the first year. I’d teased him about it. Lizard man. Cold-blooded. Do you photosynthesise? He’d laughed and said he had bad circulation and a weird stomach and liked his privacy, thank you, Tess.

And then the years went by, and he became Milo. My flatmate. My best friend. The person who’d held my hair back after my thirtieth and sat up with me through three breakups and one dead cat. The person who knew exactly how I took my tea and exactly how much I hated my job. I stopped noticing the cool hands and the peanuts and the damp bathroom, the way you stop noticing the sound of your own fridge.

Until the Tuesday I got sent home early.

It had been a disaster of a day. A dog had bitten me — not badly, but enough to need a bandage and a lecture from my boss about clinic protocol. Then a cat had thrown up on my shoes. Then my boss, looking at my face, had told me to go home before I cried on a client.

So I went home. I stopped at the shops and bought two bottles of cheap wine and a family-size bag of salt and vinegar chips. I let myself into the flat at three in the afternoon, kicked off my ruined shoes, and called out for Milo.

No answer. But I could hear him.

He was singing. Low and wordless and strange, coming from the bathroom down the hall. It wasn’t a tune I knew. It didn’t sound like anything I’d heard him sing before. It sounded like water running over stones.

The bathroom door was ajar.

In five years, I’d never seen it ajar. Not once.

I should have called out again. I know that. I should have knocked, or gone to my room, or done anything except what I did, which was walk down the hall with a bottle of wine in one hand and push the door open with the other.

The bath was full.

Not with water. With Milo.

He filled it to the brim. A great, gleaming, translucent mass, the clear blue-green of sea glass, catching the light from the frosted window and throwing it in rippling patterns across the tiles. It moved slowly, lazily, the way the sea moves on a calm day. Long, glistening tendrils draped over the sides of the tub. Some trailed across the floor. One had curled lazily around the tap. Another was idly stroking the bath mat.

And near the surface, half-formed and blurred, like a face seen through water, was Milo’s face.

His eyes were closed. He was the one singing.

I dropped the wine.

It hit the tiles and shattered. Milo’s eyes flew open — dark and wide and horrified — and the whole bath surged. The tendrils whipped back over the edge of the tub. The surface heaved. I watched his face try to pull itself together, the features sharpening and blurring and sharpening again, a nose, a jaw, a mouth opening in a silent shout.

Then a shoulder rose out of the mass. Half an arm. A hand, grabbing for the edge of the tub, the fingers stretching and dripping and not quite holding their shape.

“Tess,” he said. His voice was wet and bubbling and terrified. “Tess, wait, I can— Give me a second, I can fix—”

He couldn’t. I watched him try. The hand melted back into the mass. The shoulder slumped. His face held for a moment longer, then blurred again, like a reflection in a disturbed pond.

“I can’t,” he said, and his voice cracked. “I’m too tired. I can’t hold it. Tess, I’m sorry, I’m so sorry, please don’t—”

I sat down on the bathroom floor.

Right there, in the spilled wine and the broken glass. I didn’t decide to. My legs just went. I sat with my back against the cabinet and my knees drawn up and stared at my best friend, who was a bath full of blue-green jelly.

Neither of us said anything for a long time.

One of his tendrils crept out across the tiles towards me. It stopped about a foot away, hovering, uncertain. Then it slowly drew back.

“Say something,” Milo begged. “Please. Scream. Throw something. Anything.”

“Do you photosynthesise?” I said.

There was a pause.

Then a sound came out of the bath. Watery and choked and helpless. It took me a moment to recognise it.

He was laughing. Or crying. Or both.

“No,” he said. “I eat bugs. Mostly. And sometimes the mould in the grout. That’s why the bathroom’s always so clean.”

I started to laugh too. I couldn’t help it. I laughed until I was crying, sitting on the bathroom floor in a puddle of shiraz, and the bath gurgled and heaved with his laughter, and it was the strangest moment of my life.

When I finally stopped, I wiped my eyes on my sleeve.

“How long?” I asked.

“How long what?”

“How long have you been…” I gestured at the bath.

“Always.” His face had settled, a little. Still blurred, but recognisably him, resting on the surface of the mass like a reflection. “This is what I am, Tess. I was born in a rock pool off the point at Gull Head. My mother taught me to hold a human shape when I was very young, so I could live on land. Most of my kind do it. We’re everywhere. You’d never know.”

“And the human shape. The… Milo shape.”

“It’s real. It’s me. It’s just… a shape I hold.” He hesitated. “Like holding your breath.”

Something cold went down my spine.

“Holding your breath,” I repeated.

“It’s fine for a while. Then it gets harder.” One tendril curled slowly around the edge of the tub, tight, like a clenched fist. “Most of us only hold it when we’re out in the world. At home, we let go. Rest. Fill the bath.”

I thought about five years. About Milo, curled on the couch beside me every evening, watching terrible reality television. Milo, cooking me dinner on bad days. Milo, falling asleep sitting up on Sunday afternoons, so deeply and suddenly that I used to joke about narcolepsy.

Milo, never once in five years letting go.

“You hold it at home,” I said slowly. “All the time. Because of me.”

He didn’t answer.

“Milo.”

“Only when you’re here,” he said quietly. “When you’re at work, I come in here and let go. I’m usually done by the time you’re home.” A pause. “Today you were early.”

“Five years,” I said. “Five years, Milo. Doesn’t it hurt?”

The bath went very still.

“A bit,” he admitted. “By the end of the day. Like a cramp. It’s fine.”

“It is not fine.” My voice came out sharper than I meant. My eyes were stinging again. “Why didn’t you tell me? I’d have— You could have just— I wouldn’t have cared.”

“You don’t know that.”

“I’m sitting on the floor in a puddle of wine talking to a bath full of you. I think I’m handling it pretty well.”

That startled another watery laugh out of him. But it faded fast.

“When we first moved in,” he said, “I meant to tell you. I was going to wait a month. Make sure you weren’t a slime-hater. Then a month went by, and you were funny, and kind, and you made terrible jokes about my circulation, and I thought, I’ll tell her next month.” His face rippled. “Then it was a year. Then two. And by then—”

He stopped.

“By then what?”

A tendril crept across the tiles towards me again. Slowly. Carefully. This time it didn’t stop. It came all the way to my bare foot and hovered there, just above my toes. Waiting.

I didn’t move away.

Very gently, it settled against my skin.

It was cool. Smooth. Softer than silk, and faintly, pleasantly damp. It curled lightly around my ankle, like a hand holding mine.

“By then,” Milo said, “I was in love with you. And I was terrified that if you saw what I really was, you’d never look at me the same way again.”

The bathroom was very quiet. Somewhere, a tap dripped.

I looked down at the tendril around my ankle. At the soft blue-green light rippling over my skin. At the great gleaming mass of him filling the bath, and the blurred, frightened face of my best friend, waiting for me to tell him to leave.

I thought about five years of him holding his breath. For me.

“Milo,” I said.

“Yes?”

“Let go.”

He went still. “What?”

“When I’m here. When you’re home. I don’t want you holding your breath for me anymore.” I reached down and laid my hand over the tendril on my ankle. It shivered beneath my palm. “I want to see you. All of you. The way you really are.”