The objective of this article is to analyze Lost from the perspective of transmedia storytelling and to propose a taxonomy of transmedia expansion/compression strategies. In the first section, the article presents the basic components of transmedia storytelling from a theoretical point of view that combines narratology and semiotics. After describing the most important components of Lost's transmedia fictional universe in the second section, the article presents a general description and taxonomy of expansion/compression narrative strategies based on traditional rhetorical categories. The article also analyzes “compressed texts” – like recapitulations – and their role inside the expansive strategies.