Reading A Scanner Darkly by Philip K Dick, i'm maybe a third of the way through? Takes place a 'futuristic' or alternate reality, science fiction. The main factor in the book is 'Substance D,' this super-addictive, cheap, widely used, fatal recreational drug. The characters are believably insane. It's really interesting, some of the best imagery and phrasing i've read in a long time, and a fun one to read if you, hm, have ever participated in consumption of illicit substances 😉 Probably be done with it pretty soon.