Elias steadied his breathing, bubbles rising past his faceplate as he followed the beam of his flashlight downward. The chain appeared below, enormous, ancient, crawling across the seabed like the spine of something buried alive.
Its links were carpeted with coral and seaweed, but the metal beneath still gleamed in places where the current had scraped it clean. Edwin swam beside him, their lights cutting through the blue haze. Schools of fish scattered at their approach, flickering silver and vanishing again into the gloom.