CERTIFIABLY JONATHAN is a comedy/mockumentary that weaves in and out of the bi-polar world of Jonathan Winters, where reality and fantasy collide. Jonathan Winters, 85-year-old comic genius, is also a gifted painter who dreams of having his work hang in the Museum of Modern Art. The filmmakers show his work to a famous art critic who believes Jonathan is "the missing link between Miro and Dali" and he convinces the museum to give Jonathan a show. They agree, but only if he paints three new paintings. Jonathan launches into a creative frenzy, but disaster strikes when his favorite painting is stolen along with his sense of humor. Without his humor, Jonathan can't paint and is about to lose the opportunity of a lifetime. Jonathan sets out on a quest to get his mojo back, with the help of Howie Mandel, Sarah Silverman, Rob Reiner, Nora Dunn, Ryan Stiles, Tim Conway, Robert Klein, Kevin Dunn, Gary Owens, and the Arquettes.