In this article the authors resort to a qualitative analysis of the plot of science fiction stories about a group of scientists, written by two 11th-grade Earth and Life Science students (aged 17), and to semi-structured interviews, with the double purpose of diagnosing their conceptions of the nature of science (namely, as regards scientists' activity), and discussing the potentialities of this methodology in terms of research and education in science. The adopted methodology proved particularly effective in diagnosing the students' conceptions of scientists' characteristics, scientific activity, and science-technology-society interactions. The limited content of certain conceptions and a certain lack of knowledge on the part of the students concerning the processes and the epistemology of science highlight the need to pay explicit attention in science classes to the nature of scientific activity. Some of the ideas brought up by the students clearly show the influence of stereotypes and catastrophic scenarios depicted in films, television programs, and books, revealing media's limitations when divulging scientific and technological themes to the general public and stressing the need for the school to promote a critical debate about science and technology images conveyed by the media. Discussion of the story plot is appended.