In the shadow of a legendary filmmaker's unfinished masterpiece, a young documentarian stumbles into a mystery that could rewrite cinematic history. "Onde Jaz Orson Welles?" follows the obsessive quest of a researcher, played by Gonçalo Waddington, who becomes convinced that the final, lost film of the iconic Orson Welles holds a secret far greater than anyone imagined. His investigation pulls him into a labyrinth of forgotten reels, cryptic clues, and aging collaborators who guard their memories closely, forcing him to confront the blurred line between artistic myth and hidden truth. Blending elements of a psychological thriller with a detective story, the film crafts a tense and atmospheric journey through the ghostly echoes of a genius's last ambition, asking how far one should go to resurrect a phantom.