The author gives an ecocritical reading of a short, unfinished novel by Vladan Desnica Pronalazak Athanatika (The Discovery of Athanatik). The paper comprises three thematic units: an ecocritical approach to a thematic cycle (life – death – immortality) in the novel, compared with Homo Deus by Yuval Noah Harari; an ecocritical analysis of rain as seen from the point of view of Susan Farrell’s ideas; and an analysis of Pronalazak Athanatika in the context of two dystopian ecological/environmental novels in contemporary Croatian literature, Planet Friedman by Josip Mlakić and Mjesečev meridijan (The Moon Meridian) by Edo Popović, with a comparison to ecocritical readings of Louise Squire. The author concludes that Pronalazak Athanatika – defined in genre terms as speculative fiction – makes Desnica a predecessor to current scientific considerations (Harari) and literary works (Mlakić, Popović) in warning that ecology and ecological factors – immortality and population increases, a lack of food, and ultimately the destruction of the planet – may have destructive effects on social change, the division of power, and the shape of the future.