Alan staggered sideways, pitched head-first over the low wall and fell into the lake.

A fresh supply of yellow froth (probably the same type of elemental sulfur found in the "cool acid-brine" crater lake at Kawa Ijen) is brought up by the plume and pushed out toward the crater wall.

Deep dark green wall tiles radiate outward, bringing to mind the moment of immersion into a shady, clear lake.