Dive
A mermaid is unable to help a diver - he is hopelessly stuck.
The diver is tangled in a fishing net. The dive knife is gone. The air gauge and dive computer are in the red. There's no way to return to the surface. The diver erases a slate and writes "WILL IT HURT?"
The mermaid writes "I'm sorry. Yes it will, but it will be quick."
The diver erases the slate and writes "I AM READY."
The mermaid begins to glow, pushing back the inky blackness. Her tail is not a tail, it extends back thirty feet like a long stalk where it sprouts from the head of a monstrous angler fish. "I am sorry," she says, "truly."
The mermaid paused: "You are not a sacrifice. The others are drowned, with a hook through their feet and an air bladder about their necks."
The diver wrote "I swam here myself. I put myself on this hook."
Around him mermaids from other great fish gather the bodies from the hooks and bring them back to their monstrous roots.
"Why?" asked the mermaid, "why would you do this to yourself?"
As the other mermaids pressed the bodies up against the side of the monstrous fish tendrils extended from the fish into the men's spines. For a moment it looked as if the men still lived, as if waking from a deep sleep into a panic.
"All my life," said the diver, "All I wanted was to die young for a glorious cause. Now I can no longer die young. Let me have purpose in death. Let me serve you humbly for eternity."
The dead men on the side of the fish struggled as the mermaids cut away their clothes. One by one tendrils erupted from their mouths and eyes spreading like tree roots across their faces. The dead men fuse to the flanks of the great fish, their penises erect and leaking seed.
"Your purpose," said the mermaid to the diver, "is not mine to give."
Without another word, the mermaid swims past the diver, still trapped on his hook. He watches her anglerfish body pass him by, a man shaped depression on her flank that was never intended for him.
Alone in the cold darkness, the diver waited on his hook for a long time.