Blue straggler stars (BSSs) are mysterious and, at the same time, fascinating cosmic objects: they are expected to be the result of direct stellar collisions, or vampirism phenomena between two companion stars in a binary system. Thus, BSSs can be considered as a sort of reborn (revenant) stars, and their very existence is the manifestation that exotic phenomena like stellar collisions and vampirism are occurring in old stellar clusters. A group of scientists led by Prof. Ferraro at the Department of Physics and Astronomy of the Bologna University has discovered that young (newly-formed) BSSs prefer low density environments with respect to high-density star clusters. The discovery has been published in the 15th May 2023 issue of Nature Communications.