This chapter seeks to stretch the notion of paratext while dealing with the galaxy of heterogeneous material that constitutes The Girl with the Dragon Tattoo’s world. I will offer an explanation of the role of paratexts in terms of flexibility, fluidity, and complexity. The Genettian notion of paratext will be stretched, according to Jonathan Gray’s reading, to include official paratexts, such as DVD covers and bonus material, trailers, and posters, as well as an alternate reality game, and grassroots paratexts, such as web parodies, homages, and fan art. Paratexts, designed to be mobile, short-lived, and spreadable, are spaces in which circulatory instances, characteristic of the current media panorama, are more visible. Instead of being thought of only in terms of ephemeral “thresholds” to textuality, they can be studied as key elements of a complex narrative ecosystem. This is especially the case when they are considered sites of negotiation of meaning and translation across worlds, parts of a semiotic process through which an ecosystem adapts to the environment during its lifetime.