The aim of the paper is to discuss the ersatz theory of Lewis’s impossible worlds, point out its undeniable benefits and demonstrate its costs. Firstly, I present two approaches to Lewis’s impossible worlds taken as constructions out of possibilia. Secondly, I evaluate the proposals using the Lewisian criteria of success concerning the well defined conception of analysis. Although appealing, I do not find the proposals fully persuasive. Thirdly, I discuss the objection from an ad hoc distinction between possible and impossible worlds. I conclude that the objection does not present a special problem for the Lewisian theory. Finally, I motivate a theory of extended modal realism, to wit, modal realism enriched with concrete impossibilia.