Fever Dream is a short, read-it-in-a-day volume, and that's appropriate. Like a real fever dream, it's intense, and not something you'd want to drag out any longer than necessary.
Which is not to say it's not worth reading. I could hardly put it down. The premise is deceptively simple. A woman is sick in bed, dying, and she's talking to a young boy. He is not her son. How they're connected, how she became sick, why she's dying, and what happens along the way, that makes up their conversation (the book is entirely in dialogue, but it works). And what, exactly, did happen? Something mysterious. Something related to an environmental disaster.
Or is it? Or is she hallucinating? Is any of this real?
There are clues and repeated motifs. The woman thinks repeatedly about "rescue distance": the distance required to rescue her young daughter at any given time. Ropes tightening. A green house. Horses. Ducks. All in a style that's both hallucinatory and hyper-realistic at the same time.
This is a book that continually forces the reader to question what's happening, what's real, what's not, in a good way. Even after finishing it, I'm not entirely sure what I think happened--but it did make me think.