The article explores the construction of boundaries, alterity and otherness in modern science-fiction (SF) films. Boundaries, understood as real state borders, territoriality and sovereignty, as well as the construction of the other beyond an imagined border and delimited space, have a significant meaning in the dystopian settings of SF. Even though SF topics are not bound to the contemporary environment, be it of a historical, technical or ethical nature, they do relate to the present-day world and transcend our well-known problems. Therefore, SF offers a pronounced discourse about current social challenges under extreme conditions such as future technological leaps, encounters with the alien other or the end of the world. At the same time...