Upside Mystery Legacy

Upside Mystery Legacy is an upcoming American fantasy mystery comedy film, produced by MGM Animation Studios and Spyglass Media Group. It'll be the fourth and final main installment of the Upside Mystery franchise, directed by Simon J. Smith from a screenplay by Jeff Gunn, Will Schifrin, and Ray DeLaurentis. The film stars the reprising roles of John Travolta, Christian Slater, Michelle Rodriguez, and Christina Ricci, with Kate McKinnon, Bill Hader, Olivia Newton-John (in her final role), Jenna Ortega, Nick Kroll.

Upside Mystery Legacy is scheduled to be released in the United States on July 7, 2023, by United Artists Releasing.

Premise
Hans Truman retires in San Paradise from solving mysteries after failing to catch who did it. However, Jason Truder and Stella Lee still receive the unknown last mystery from the Upside Mystery headquarters, and they convince Truman to come out of his retirement on a terrifying last mystery.

Cast

 * John Travolta as Hans Truman, a legendary detective.
 * Christian Slater as Jason Truder, Truman's best friend who was also good in solving mysteries.
 * Michelle Rodriguez as Stella Lee, a spy agent who is Hans Truman's love interest.
 * Kate McKinnon as Meryl Farr.
 * Bill Hader as William Wilson.
 * Olivia Newton-John as Bianca Tuffin. This will be Olivia Newton-John's final role, following her death in August 2022, and this film will be dedicated to her memory.
 * Jenna Ortega as Samantha "Sammy" Mintz.
 * Nick Kroll as Andrew Slatter.
 * Christina Ricci as Kelly France, a former physicist who became the new boss of the Upside Mystery headquarters, replacing Rose Elizabeth.

Production
Discussions about a fourth film began in December 2015. The film was officially announced in 2019 that the fourth film was in development. It was also announced that the film will be titled Upside Mystery Legacy and will feature the reprising roles of Travolta, Christian Slater, and Michelle Rodriguez. In an interview during the 15th anniversary of Upside Mystery, voice actor John Travolta mentions that the fourth installment will be the last in addition to the announced new cast members Kate McKinnon, Bill Hader, Olivia Newton-John, Jenna Ortega, and Nick Kroll. In September 2022, Christina Ricci confirmed that she will reprise her role as Kelly France from Upside Mystery 3.

Unlike the first 3 Upside Mystery films, which were provided by Arc Productions, the animation will instead be provided by Cinesite in Montreal and Vancouver. In addition, it will be the first MGM Animation Studios film to have its animation provided by MGM Animation Canada in Montreal.

Release
Upside Mystery Legacy was scheduled to be theatrically released on July 7, 2023, by United Artists Releasing in the United States and Warner Bros. Pictures internationally. It'll be released in theatres, RealD 3D, Dolby Cinema, IMAX, 4DX, and ScreenX.

Video game
In October 2022, it was announced that MGM would collaborate with Skydance New Media for a tie-in game.