Episode Thirteen by Craig DiLouie

 

This is labeled as an epistolary novel, but that's not entirely right. There are entries that could not possibly have been written, from the narrative; and most of the "entries" are in fact more like transcripts of audio (with weirdly knowing descriptions of what body language and expression mean, insight into what people are literally thinking). Honestly, this reads more like a script, for the most part, than a novel--and I think the format makes what I've seen called the "fictive dream" more elusive than actual straight prose. The fact none of the characters are particularly likeable, or come across as anything like as intelligent (or brave, or driven, or ...) as they seem to think they are doesn't help much, either--though there's a hint that one of the characters might have survived in a more meaningful manner than the one who was subsumed into the Bad Place.