He didn’t remember downloading it. It had appeared after a late-night dive into an abandoned forum dedicated to "lost" Brazilian folklore. In the myths, Iara was the Lady of the Waters—a mermaid who lured men to the depths of the Amazon. But this wasn't a myth; it was 4.2 gigabytes of encrypted data.

The video was shaky. It showed a research team standing on the muddy banks of a black-water creek. The air in the recording seemed thick, vibrating with the sound of cicadas that grew so loud they became a physical hum. One researcher, a woman named Dr. Broin, stepped toward the water. She wasn’t looking at the camera; she was looking at something under the surface that the lens couldn't quite catch.

The hum in the room grew deafening. Looking down, Alex saw a thin layer of dark, brackish water seeping from beneath his keyboard. It smelled of crushed lilies and ancient silt. He looked at the monitor one last time. In the reflection of the black screen, he saw Dr. Broin standing directly behind his chair, her hair dripping, her eyes two dark pools of endless, rising tide.