It wasn’t just fire.  It was black fire, fire surrounding him that he couldn’t see in the darkness, so that he had no idea which way to go unless he burned himself half to death.  It was the dread which suffocated him more than the smoke, crushing every thought, and the exhaustion that fought it.  If I give up, I’ll die, but if I die, I can give up, but if I give up, I’ll die…
He staggered onward through this nightmare, this pointless and endless nightmare, so long that he had no idea how long he’d been there.  He didn’t worry about if it was real or not; the torture drove everything else from his mind.  Blood pooled across the unseen floor.  The ceiling got lower and lower until he had to crawl.  And that invisible fire seared him every time he made a wrong turn.  Where was he?  What was the point in this?  Where was the end? 
But what disturbed him and scared him more than anything else was the screams of his family, always behind him, never dying.  Ceaseless and infinite pain.  He would have shut the book or turned the TV off or unplugged the Xbox long ago, but this was not a novel or a movie or a video game. 
Finally he stopped and fell to the floor.  The invisible flames were an oven.  He couldn’t move anymore.  What else could he do?  Going on was pointless.
Something appeared in the blackness.  It was dark green, and strangely peaceful.  He watched it grow stronger, pulling closer to him. 
It had no shape or depth.  It was simply a bit of color.  He felt like it was staring at him, staring into his soul.  All the dread and pain and even his family’s screams faded into comfortable quiet. 
It shattered.
And they were back, louder and more ridiculous than before. 
But he kept watching the piece of green color.  It didn’t disappear.  No, instead it shuddered and began to pull itself together. 
It refused, whispered a voice in his head.
With that, a huge and jubilant hope like nothing he’d ever felt flared in him, and the green expanded, showing him where all the flames were, where all his family was.  He was shaking and roasted alive by the fire, but he could see the reason to move now. 

He got back up and kept going.  To save them, and himself.

He awoke in the morning with a strange feeling of great resilience, like he should immediately get a journal and write that weird nightmare down. 
But…it was already gone.