He didn't mean for him to die.
The bubbles of air escape from his companion's nose, like seconds of life popping in the water, and Arthur decides it's an accident. The lad had been so eager to learn, so excited to see a member of the Merfolk, as Arthur is, that he was all too willing to come into the water with him. A few hours of talking and he'd been pliant, been willing, been all too happy to slip in beside Arthur and take his hand to his death.
Of course, it was an accident. Sometimes he forgot that humans can't hold their breath for long. Sometimes it slips his mind that the swim to his city is long, that the lad may not want his last sight to be its coral and stone glory, its underwater brilliance.
Sometimes he looks at their faces, and sees the fear and panic etched onto them, and wishes they would just smile again.
Arthur hasn't looked at the human's face yet - Alfred, he thinks his name is. Occasionally he'll prefer not to see their expression distorted, and after Alfred's bright, beaming smile he thinks it'll hurt him more than it ought.
Really, it's an accident. It is.
He tries to save a few of them, changes his mind and tries to give them air or gouge them gills, but all it ends in is futileness, or blood and flesh strewn through the water; and then more often than not he has to leave them to the sharks, and can't return them home like he always intended.
Alfred's home is so far away, and Arthur's yet further, his tail propelling the two of them down lower and lower, and he notes absently that Alfred has gone limp. At first he was swimming alongside him, deep into the water, but then when he tried to return to the surface Arthur had grabbed him, and Alfred had struggled, been confused and frightened; but now he is still, and Arthur wonders whether he has gone from this world.
He resists the urge to check and swims quicker, holds Alfred's hand firmer, his own webbed hand and sharp nails digging into the human's flesh. Arthur bares his sharp teeth at the fish that swarm near them, the opaque green orbs of his eyes otherwise focused straight down. The incessant need to see if his companion has departed weighs on him, for this is futile if he has, and he'll have to return him, and...
A pain, sharp and strange punches his chest, and it's nothing physical, nothing in the water around him - but from within him, he feels it, and an unbidden image of the lad smiling breaks into his vision. He shouldn't feel this - he knew the human for mere hours, just wanted somebody to see his home and live, to love it like he. But he knows from experience that the longer you wait to show someone something magnificent, the less likely it is that they'll ever see it, and so he drags them down long before they're ready.
The image pressures him to turn towards his companion, and he does so, his head tilting to the side to see whether he has failed this time too.
... and there Alfred is.
Smiling at him.
Arthur is so taken aback that he stops swimming, falters in the strokes of his tail and stops dead, which is surprisingly what Alfred is not.
He stares at this human lad whom he took from his home, willingly only at first. He watches the way his eyes, the colour of the sky reflected in the surface of the ocean, crinkle at the edges, unobscured by the glasses they left far behind, safe and dry.
Arthur watches the way Alfred's mouth is turned up, the way it opens willingly to grin gently at him, and how he reaches forward with the hand not in Arthur's grasp to touch the side of his face. The lad leans against him, bare chest to scaled chest, and leans against his shoulder in a manner that is almost tired. The pain returns, as with a sigh of small, hopeless bubbles, Alfred releases what seems to be his last breath, chokes in water, and then stills, apparently unconscious. Lost.
Arthur panics.
No human has ever died in his arms in this way, none have ever smiled at him when he has in effect murdered them, drowned them, by taking them somewhere they don't belong in order to have some companionship he doesn't deserve. No human has ever looked at him with such an expression and made Arthur want to wail, even if he's never felt this way before. He's regretted, he's been sad, but this... this is...
He's known him for mere hours, and yet the loss of him is suddenly greater than anything he has ever felt.
Arthur twists, grabs Alfred tight to his chest, and pushes water with his tail to propel them upwards now. They're so far, and the man is dead, but he knows he can bring him back if he gets there in time. There is something about their minds, something about oxygen, that gives him that barest of time before he's beyond saving.
... saving. Is that what he's doing?
Arthur has never saved anyone before, but he's tried. As the water pushes past them and makes Alfred's hair twist this way and that, Arthur wishes he could breathe its smell, and Alfred's; the smell of life, when all around him are those he caused to face their death.
It seems too long to the surface, but at last he breaches it, at last he breathes the clear air, and hefts Alfred's face and chest as much above it as he can. He tries to save him, right there in the water, for there's no time to reach land. He isn't sure what to do, so he hits his back to try and dislodge water, he tries to give him air straight into his mouth, past lips too cold and clammy to be satisfying - be it with the promise of life or the chance of love - and tries to push against his heart, to start it again, but everything is difficult in the shifting waves, and he cries out in distress.
The body is heavy in his arms, and limp against his body, and he holds Alfred's head up with one hand and tries to implore him to breathe. He keeps them pressed together, refuses to let the waves take him, and the pain in his chest is so strong now that he can hardly breathe himself.
There must be something he can do, there must be something.
He didn't mean for him to die.
A/N: I was considering doing a companion piece to this, the same scene from Alfred's point of view. If anyone is interested, I'll likely do it as a second chapter.