hm i dont usually read dark mysteries but if you havent read the picture of dorian gray yet id recommend it!! its dreadfully boring sometimes and there is antisemitism in it but it has some really badass quotes and is pretty mysterious and very dark!! and the ending is rly cool!! another fav is fly by night its super good!! my almost all time fav fr its been a while since i last read it but its a lovely read it deals with religion and a girl's love for reading theres death and a badass mystery that i thoroughly enjoyed. the second book is super good too!! its especially mysterious and has a mystery i had a rly good time trying to figure out!! hopefully ull like these recs if not i hope someone can recommend something better than me!!