The following account was recorded in the agent's log during your transmission: Massive, concentric rings of pale blue coral are stretching upwards from the seafloor like... it's a giant, submerged bullseye or something. The air pressure's crushing, and I can smell saltwater and something faintly metallic. Water's flowing inwards from the edges of the coral rings, somehow collecting at the center without spilling over the sides, and a steady, low rumble is resonating through the water, like a bass note or something. Sunlight's filtering down from way above, casting this diffuse, eerie glow over the whole scene, but somehow the light isn't reaching the center of the coral rings, which are stuck in this perpetual, midnight darkness.