Frederick Fitzell is living his best life—until he starts having horrific visions of Cindy, a girl who vanished in high school. After reaching out to old friends with whom he used to take a mystery drug called Mercury, Fredrick realizes the only way to stop the visions lies deep within his own memories, so he embarks on a terrifying mental odyssey to learn the truth.
After the idol group Aqours has won the final Love Live! contest, its remaining members prepare to enroll at a new school only to run into some unexpected trouble while the former members go missing on the way to their graduation trip. Separated, the girls begin to realize the value of their friendships as they attempt to find a solution to their various crises.