Hopping nimbly down into the tunnel, you set off immediately, checking only to confirm that the surface of the tunnel is in fact perfectly smooth. As you head east, you notice that the tunnel slopes gradually downwards
Unfortunately, a few dozen metres down, you hear the sound of the fireball behind you, and the tunnel begins to brighten. Unable to go back, you sprint forwards, and in a few seconds the downward slope has become a steep, curving slide. As you slip forwards and start careering down the smooth surface, the sound of the fireball becomes deafening, and it catches up with you.
The white fire engulfs you as you lose contact with the surface and begin to fall. Unfortunately, before you can strike any surface below, your flesh and even bones are superheated and incinerated by the arcane trap. What little remains drifts slowly downwards, only to be totally annihilated by the fireball on its next pass.
Go back and pick a different course of action!