Atelier Sophie: The Alchemist of the Mysterious Book DX is a role-playing game developed by KOEI TECMO GAMES CO. It is available on the Nintendo Switch platform and is a part of the Mysterious series. The game revolves around a young alchemist, Sophie, and a sentient book, Plachta, on an adventure to recover Plachta's memories and gain alchemic knowledge.

The game offers new episodes of Sophie's growth and a new costume that will help her follow in her grandmother's steps. It also has three new cauldrons to assist in your adventures, a sprinting option to make getting around easier, and a 'Fast Forward' feature for fast-paced battles. The game includes previously released DLC and a photo mode to enjoy capturing beautiful images.

Note that this title can also be purchased as a part of the discounted "Atelier Mysterious Trilogy Deluxe Pack," together with "Atelier Firis: The Alchemist and the Mysterious Journey DX" and "Atelier Lydie & Suelle: The Alchemists and the Mysterious Paintings DX." The English version includes English voice, although some events do not include English voice.