Professor Jiménez (Manuel Noriega) supports the theory that the retina actually retains the last image seen by the eyes before death. Although most of his colleagues ridicule the thesis, his student Eduardo (Julián Soler) stands behind him. Eduardo loves Marta (Amelia de Ilsa) but her father (Miguel Arenas) opposes the match. Eduardo assists Jiménez in his experiments and helps him steal recently deceased bodies to prove his theory. Caught in the act, Eduardo is badly wounded by the police, but nonetheless manages to escape and return to Jiménez's lab. Jimenénez calls Marta, and she is the last thing Eduardo sees before he dies. A photographic plate of his retinas reveals the image of his girlfriend. Jiménez is reinstated at university and dedicates a lecture hall in Eduardo's name.