Obsidian Moon Crate is a newer book box based in the US that focuses on adults with interest in the darker elements of life and books. Each box comes with a new hardcover book, one crystal, one candle, and four to six other items.
The items included in this box are a full size bath soak inspired by the Winternight Trilogy, a Snow Maiden wood wick candle, a wooden sign, a His Dark Materials enamel pin, peppermint hot cocoa mix, and an opalite crystal star.
The book included was a hardcover copy of The Midnight Girls by Alicia Jasinsk. This edition also came with an author letter, a signed book plate, and purple sprayed edges. The story features two rival women who each want to steal the pure heart of the prince. If one consumes a pure heart they will gain immense power. But as their attraction to each other grows their rivalry might cost both of their lives.
Overall, if you are interested in a darker aesthetic or darker book this could be the book box for you. I do plan to order other boxes from them in the future.