Layton's Mystery Journey: Katrielle and the Millionaires' Conspiracy is a puzzle adventure game for the Nintendo 3DS. It marks the seventh main installment in the Professor Layton series. Players assume the role of Katrielle Layton, the daughter of the famous Professor Hershel Layton. Set in London, she runs a detective agency and takes on various cases, many of which tie into a larger mystery involving seven wealthy individuals. The game features a collection of brain-teasing puzzles and riddles, alongside charming animated sequences and a whimsical storyline, distinctive of the Layton series.