human
Make a concise location description of a serene lake in the wilderness with trout and a dark shape.
assistant
From on top of the black rock promontory, the depths of the tarn can be seen through the clear crystal water. Far beneath, the obsidian reef dives steeply to the lake bottom that deepens beyond visibility toward a bright orange glow. A large dark shape, deep in the water, scatters schools of trout.