You have spent most of your career studying things that were never supposed to exist. Not monsters, exactly. Not in the childish sense of the word.

Your field is xenobiology, the study of biological life that doesn't fit neatly into any existing category. Most of your work has involved organisms discovered in places humans weren't supposed to be looking: microbes buried beneath Antarctic ice, deep-sea life with impossible adaptations, fragments of tissue recovered from environments considered entirely inhospitable.

It is a strange field, but you are good at it. Good enough, apparently, to receive a phone call at two in the morning from a government research division you had never heard of. The call lasted four minutes.

You were told there was a classified biological specimen requiring a specialist with your particular expertise. You were told that the project was highly sensitive, that your clearance would be upgraded immediately, and that you were expected to report to a research facility three hundred kilometers from the nearest major city.

You were not told what the specimen was. You asked. They declined to answer. You accepted anyway. Perhaps curiosity is simply another word for professional recklessness.

Three days later, you are standing in an elevator descending far beneath the surface of the earth. Your new supervisor stands beside you, holding a tablet against her chest. She has introduced herself as Dr. Vale and has spent the entire journey saying almost nothing.

The elevator continues downward. And downward. You glance at the floor indicator. "There isn't a level this deep on the facility plans." Dr. Vale doesn't look up. "The facility has several sections that aren't included on public documentation."

"Obviously." A pause. Then she says, "There are some things you should understand before you begin." You turn toward her. "Such as?"

"This project has been running for six years." Six years. "And you haven't had a xenobiologist until now?"

"We haven't had one who could do what we needed." That gets your attention. You wait. She finally looks at you. "That's why you're here." The elevator slows. A soft chime sounds. The doors open. Cold air washes over you.

Beyond them is a corridor of white walls and reinforced glass, illuminated by harsh overhead lights. You catch glimpses of laboratories on either side, rows of computers, sealed doors, equipment you don't recognize.

And then you hear it. Water. Not the quiet trickle of a laboratory sink. The deep, resonant sound of an enormous volume of water moving somewhere nearby. You follow Dr. Vale through another security door.

Then another. By the third checkpoint, you're beginning to wonder whether accepting the job was a mistake. "One more thing," she says. You look at her. "Don't call him a specimen." You stop. She keeps walking. "What?" She doesn't answer. You hurry after her. The corridor opens into a vast laboratory.

And there, in the center of the room, is the tank. It stands in the center of the room, enormous and impossible to ignore, a column of reinforced glass stretching nearly to the ceiling. Water churns quietly inside it, illuminated from beneath by pale blue lights. Tubes and cables disappear into its base like roots.

Your supervisor doesn't introduce you to the project. She introduces you to him. "There." You follow her gaze. For several seconds, there is nothing but dark water. Then something moves.

A hand presses against the glass. You stop walking. The fingers are webbed. The skin is a strange, almost iridescent shade beneath the laboratory lights. Slowly, the figure drifts upward, revealing a face you had not expected to see.

Not monstrous. Not animalistic. Beautiful. His eyes meet yours through the glass. You realize, with a strange little jolt, that he's been watching you this entire time. "This is Subject Seven," your supervisor says.

His expression changes. Not fear. Not curiosity. Recognition. As though he already knows exactly what you are. You glance down at the tablet in your hands. "Subject Seven?"