Close to the start of her hypnotic documentary The Memory of Butterflies, director Tatiana Fuentes Sadowski describes the moment that inspired the film. While looking through a selection of propaganda images taken by a company operating in the Amazon during the late 19th-century rubber boom, Sadowski came across a posed portrait of two young Indigenous men. In the image, the pair stands hand in hand dressed in Western clothes, stiff suits and ties, gazing at the camera with solemn, unreadable expressions: Omarino and Aredomi. Documentary spoke to Sadowski shortly after the film’s premiere at the Berlinale, where the documentary jury awarded the film a special mention, about the ethics of colonial archive, cinematic speculation, and sound as a threshold. This interview has been edited for length and clarity.