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 west, you notice that the tunnel slopes gradually downwards
Unfortunately, no amount of time prevents you from meeting the fireball a few dozen metres along.
The sound and light starts up in earnest, and though you are protected from the glare and immediately turn and sprint the other way, the fireball effortlessly catches up with you.
The last thing you see is the tunnel, solid red through the sunglasses, before your body is rapidly shrivelled and then incinerated by the incredible heat.
Go back and pick a different course of action!