Let's take a dark room. Celeste Rojas Mugica and her father Lucho lock themselves in it to develop images of the past. This past is Chile during the Pinochet years. Lucho Rojas was a photographer there but also an opponent of the regime, and therefore clandestine. His life oscillated between taking photos of the present and making himself invisible – between light and shadow. "The exercise consisted of, and still consists of: closing your eyes and imagining a place": the method and discipline of the clandestine. This sentence, the first in the dialogue between father and daughter that constitutes the framework of Une sombra oscilante , also formulates the theoretical hypothesis of the film: considering the image not from the point of view of the visible object, but from the faculty of imagination. In this singular dark room, development is no longer a solitary technical operation of revelation, but a poetic and political process of imagination for two. Developing the image means describing it not to exhaust its meaning but to flush out its parts of shadow, uncertainty, and therefore power. It is to extend it through words to imagine the story of the past, or to do it in one's head, with one's eyes closed, to project a future. The game is serious, but also very joyful: plastic inventions and ideas follow one another at an astonishing speed, all punctuated by an editing that combines freedom and rigor as rarely before. Brilliant and seductive, Una sombra oscilante profoundly renews the filmic approach to the photographic archive by inventing a cinematographic form that seems to be born from the very process of creating images – taking, developing. A dark chamber music, with four hands and two voices, draws the spectator into a captivating oscillation between the possible and the real, between what has been and what could have been, what is and what could be. In our dark times, here is a film that projects a light that is all the more joyful as it is intermittent – ​​it does not forget the shadow from which it comes.