Lithely jumping forwards, you land on the curved inside of the tube. Feeling with your fingers, you find that the ground is indeed perfectly smooth, like glass.
You are considering your surroundings when you notice that the glow from the left has brightened considerably, and the noise is growing louder.
You are just considering that perhaps jumping down wasn't such a good idea, and trying to get back up the smooth side to the passage opening, when the light grows to blinding levels. You are almost unsurprised as the three-metre white fireball screams towards you at some unbelivable speed.
The air is already growing hot.
With the howling, burning sound, much louder now you are in the echoing, tunnel, drilling into your brain, and blinding light reflecting from every angle, you fall to your knees. With hands futilely covering your ears, and eyes screwed shut, you are powerless to prevent the ancient arcane trap from incinerating your body.
All that remains is a black smear of ash, and even that is swept clean when the fireball makes its next pass.
Go back and try a different choice!