A realistic first-person view descending slowly through a narrow vertical underground shaft filled with water. The shaft walls are metallic and damp, reflecting light from a soft spotlight. Small particles float in the murky water. As the descent continues, a wider underground chamber appears at the bottom. Resting at the base of the chamber is an old wooden treasure chest with metal bands and a central lock. It is slightly tilted against a stone wall. The scene is calm, immersive, and cinematic, with soft underwater lighting and a quiet, mysterious atmosphere