Far off the coast of Altheris, where jagged cliffs met the roaring ocean, lay the Tidal Caves—a network of labyrinthine sea caves hidden beneath centuries of crashing waves. Accessible only during the lowest tide, the caves were cloaked in mystery. Locals spoke of echoes that didn’t belong to their voices and a glowing phenomenon that pulsed like a heartbeat deep within the rock. Few dared to venture inside, but young Callen had always been drawn to the unknown. Callen was a marine biologist on a sabbatical, weary of sterile labs and endless grant proposals. Determined to reconnect with the raw beauty of the natural world, they had come to Altheris on the advice of an old professor who had cryptically said, “Find the heart of the sea, and you’ll find yourself.” One moonlit night, armed with waterproof boots, a sturdy flashlight, and a journal, Callen made their way down the cliffside path to the caves. The tide was at its lowest, revealing a narrow, slick entrance. As they stepped insi...