The aim of the article is to analyse Michel Bernanos’ fantastic series The Other Side of the Mountain from an ecocritical perspective (among others, the literary text as L. Buell’s “green script”). The series first published in the sixties, constitutes an integral part of the well-known Angoisse collection edited by the publishing house Fleuve Noir, and its author is one of the most prominent figures of the "Fleuve Noir school of the fantastic". The innovative character of The Other Side of the Mountain consists of merging emblematic fantastic elements with protoecological ideas, which were, however, popularised by deep ecology only in the nineties.