The first fish was known as the Great Shadow, although no one had ever seen its body.
It inhabited a shallow river running through a valley of white stones. At midday, when the sun stood directly overhead, its shadow passed over the riverbed, darkening the stones and the water between them. The shadow was shaped like a fish, with a long dorsal fin and a tail divided into three lobes. It was so large that the river disappeared beneath it, and the white stones became black.
At first, the villagers believed it to be the shadow of a cloud. But clouds passed overhead without changing it, and on moonless nights the shadow remained.
One morning, a boy saw the shadow move against the current. He followed it upstream until it entered a narrow gorge, where it narrowed to a dark thread and vanished between two stones.
The next day, the gorge was filled with water.
The river had risen, though no rain had fallen, and beneath its surface swam a fish no larger than a finger. It was entirely transparent, except for a single black fin. Wherever the fin moved, the water deepened.
The boy watched it disappear into the distance. Far downstream, the villagers found that the river had become deep enough to float a ship.
They called the small fish the Shadow’s Child, and entered it in the village register as a separate species.
No one thought to record the ship.
The second fish was called the Cartographer.
Its scales contained landscapes. Each scale held a different country, complete with mountains, rivers, cities and forests. The landscapes were not representations of places that existed elsewhere. They possessed their own weather, their own seasons, their own migrations of birds.
When the fish swam, the countries shifted beneath its skin. A mountain range passed from one scale to the next; a river divided into several rivers, each entering a different sea. Cities grew at the borders of forests, and forests advanced across cities, covering their towers with leaves.
The fish was captured in a net of fine silver thread and placed in a glass tank. It did not struggle. Its landscapes continued to change.
A scholar was summoned to describe it. He examined the scales through a magnifying lens and drew a series of maps, one for each visible country. He gave the rivers names and numbered the mountains. He classified the cities according to their shapes and the forests according to their foliage.
When he returned the following morning, the maps were wrong.
The fish had moved a single fin during the night. This had caused the countries to rearrange themselves. A river now passed through a mountain, a city stood beneath a lake, and a forest had grown around the fish’s heart.
The scholar made new maps.
By evening, the maps had become obsolete again.
On the third day, he removed the fish from the tank and released it into the river. It swam away, its scales glittering in the afternoon sun.
The scholar kept his maps. He bound them in a leather volume and placed the volume in the library.
Years later, when the library was demolished, the book was found to contain a small quantity of seawater. Between its pages lay a single silver scale. Within the scale was a country whose mountains had not yet appeared on any of the maps.
The third fish was beautiful from a distance.
It moved through the ocean with the slow grace of a floating flower. Its body was a delicate rose colour, and its long fins trailed behind it like translucent veils. Tiny points of light shimmered beneath its skin, forming patterns that resembled constellations. When it turned, the ocean brightened around it.
Sailors who saw it from their ships described it as the loveliest creature in the sea.
Those who came closer gave a different account.
Its scales were not scales but thin, overlapping mouths. Each mouth contained a row of small white teeth. Its fins were composed of countless pale fingers, each bearing a transparent nail. Beneath its rose-coloured skin, a multitude of tiny faces moved slowly towards the surface, pressed together as if trying to escape.
The fish did not attack. It drifted among the sailors, its many mouths opening and closing without sound. Wherever its fins brushed the water, the faces beneath its skin became briefly visible.
One sailor fell overboard. His companions saw him floating beside the fish, apparently unharmed. Then the fish turned its head, and the sailor’s face appeared among the faces beneath its skin.
The others hauled him aboard.
He was unchanged in every outward respect. He spoke, ate and slept as before. But when he looked into a mirror, his reflection seemed to be standing a little farther away than it should have been.
After some weeks, he left the ship at a foreign port and was never seen again.
The captain entered the fish in his log as Rosa mirabilis, the marvellous rose fish. He added a note concerning the unusual structure of its scales, but made no mention of the sailor.
The log was preserved in a maritime museum. Visitors admired the captain’s handwriting and the elegance of the drawing he had made of the fish.
In the museum’s great glass case, beneath the logbook, lay a single rose-coloured scale.
Sometimes, when the galleries were empty, a face appeared within it.
The fourth fish was difficult to describe because it seemed to be made from the absence of everything around it.
It was first observed in a lake surrounded by black reeds. Wherever it passed, the water appeared to have lost its colour. The reeds became invisible against the banks, and the mountains reflected in the lake disappeared from the surface.
The fish itself had no visible outline. Its presence could be inferred only from what was missing.
A flock of white birds flew over the lake. As they passed above the fish, one bird vanished from the flock. The others continued on their way, but their formation had changed, and the space left by the missing bird seemed larger than the bird itself had been.
A fisherman cast his net into the lake. When he drew it up, the net was empty. Yet one of its meshes had disappeared, leaving a hole through which the fisherman could see the lake’s bed, although the water between them remained.
He repaired the net and went home.
That night, the lake disappeared.
In its place lay a hollow in the ground, perfectly dry, with the black reeds standing around its rim. The mountains were gone from the horizon. The moon shone above the hollow, but its reflection was nowhere to be seen.
By morning, the lake had returned. The reeds were green, the mountains stood in their accustomed places, and the fisherman’s net hung intact in his shed.
He never returned to the lake.
Some naturalists maintained that the fish had been an optical phenomenon, others that it was a species adapted to conditions in which visibility itself had become a form of nourishment. A third school proposed that it was not a fish at all, but a temporary failure of the world to provide an appearance.
None of these explanations was accepted universally.
In the official catalogue, the species was entered as Piscis absens.
Beside the name, the space reserved for its illustration remained blank.
The fifth fish was discovered by a woman who had been gathering shells on a beach after a storm.
It lay in a shallow pool among the rocks, its body made of clear water, although the pool itself was filled with seawater. Within it moved a smaller fish, and within that fish another, and within that one another still, each swimming in a different direction.
The woman bent over the pool.
The outer fish opened its mouth. The innermost fish turned and opened its mouth in precisely the same way. Between them, the smaller fish continued swimming, their movements neither identical nor wholly separate.
The woman noticed that one of the fish was missing a fin.
She looked again. The fin was present, but it belonged to a fish farther inside. Another fish bore the shadow of the missing fin, and another contained a small pale shape that might have been the fin’s reflection.
The woman stayed until the tide began to rise.
When the sea entered the pool, the fish separated. Some swam towards the open water, others towards the rocks, and one slipped into a crack so narrow that it could not possibly have contained it.
The woman returned the following day. The pool was empty, but a small circular depression had appeared in the rock. At its centre lay a drop of water that did not evaporate, even in the hottest weather.
She visited the pool for many years. The drop remained.
Eventually, she brought a naturalist to see it. He examined the depression, tested the water, and made careful measurements. He could find nothing remarkable about it.
When he left, the woman looked down and saw that the drop had become a tiny transparent fish.
It was swimming in a sea no larger than a fingernail.
The current connected all these fish, although no river or ocean could be traced between their habitats.
It passed through the valley of white stones, beneath the Cartographer’s ocean, around the black reeds and through the narrow cracks in the rocks. Sometimes it moved visibly, carrying silver threads of light. Sometimes it was detectable only by the direction in which leaves turned, or by the slow bending of grass in a wind that did not touch anything else.
The naturalists attempted to map it.
They marked the places where the fish had been seen, drew lines between them, and proposed a system of underground channels. Their maps became increasingly elaborate. Some included the rivers of the Cartographer’s scales; others showed the dry hollow where the lake had disappeared. One map contained a blank space so large that it extended beyond the edges of the paper.
The maps disagreed.
The naturalists met to discuss the discrepancies. They argued about habitats, migration, reproduction and the possibility of a common ancestor. They divided the fish into families and subfamilies, then subdivided the families again. They devised new terms for transparent flesh, landscapes contained within scales, and the apparent absence of a creature from the space it occupied.
At last, they produced a great volume entitled A Complete Natural History of Impossible Fish.
It contained hundreds of descriptions, dozens of maps, and an index that referred to several species not mentioned anywhere in the text. Its final chapter discussed the current, concluding that although its existence could not be demonstrated by conventional means, the evidence suggested a common medium through which the fish might be related.
The volume was placed in a locked cabinet in the museum.
For many years, nothing unusual occurred.
Then, one morning, the curator discovered a small wet patch on the floor beneath the cabinet. He wiped it away. The following day, another appeared. On the third day, a thin line of water ran from the cabinet to the door.
He unlocked the cabinet and removed the book.
The volume had swollen. Its pages were damp, and the ink had begun to spread. When he opened it, the maps appeared to have altered. Rivers had moved. Mountains had shifted. In the blank space at the edge of the last map, a small silver fish was swimming.
The curator turned the page.
The fish was gone.
He turned back. It had reappeared, this time with a dark fin and a long shadow that extended beyond the map’s border.
The curator shut the book and called for assistance.
By the time the other museum staff arrived, the water had disappeared. The cabinet stood dry and empty. The book was found on a nearby table, its pages clean, its maps unchanged.
Only the index had been altered.
At the very end, beneath the final entry, a new name had appeared.
There was no description, no reference number, no indication of where the fish had been seen.
The name was written in a hand none of the staff recognised.
It read:
The Fish That Has Not Yet Appeared.
Far beneath the oceans, where the current passed through the dark between one world and another, a fish opened its eyes.
Its body was covered in scales that reflected no light. Within each scale lay a small, still landscape: a valley, a mountain, a river, a city, a plain of white stones.
The landscapes were empty.
Then, in one of them, a small shadow moved across the ground.
The fish turned.
All the landscapes turned with it, and in each one something began to swim.



