Initially I thought it was my tuba de plastica. Then I started coughing. Looking up I saw big sparks and thick black smoke being carried down on the strong draught. My carbide must have caught the bush at the top on fire. My first thought was to swap to ascending gear and put it out, but I started feeling asphyxiated, coughing with the smoke in my eyes. Outside a mile high smoke column was beginning to form. All I could think of was to go down. Down to fresher air. Down to the rebelay (the bush was under the Y-hang). Suddenly the theme tune from "London's Burning" streamed through a small fissure in the rock and Alex appeared from the smoke a bare four feet away. "Come on, let's keep going down."