Publisher's blurb: Having made it successfully through Tomb of Annihilation, your characters have found themselves in possession of the Black Opal Crown, and artifact rumored to be the key to returning Dendar the night serpent to the material plane and bringing about the end of the world. In this adventure your characters, navigate the temptations of the black opal crown, discover the truth behind its legends, and either prevent the end of the world, or start it.