This article examines the creation of three speculative environments within the Museum of the Future (MOTF), a virtual-reality environment (VRE) designed by Dstl to promote awareness of future defence and security technologies. In contrast to other areas of the MOTF, these speculative settings are experimental, and are intended to highlight the uncertainty of the future, using techniques of cognitive estrangement and other appropriate narrative and world-building techniques to encourage audiences to query their anticipatory assumptions and cognitive biases. The aim of this project is therefore to promote cognitive flexibility, enhance futures literacy (FL), and ameliorate against the effects of knowledge shields. After a brief overview of the three speculative environments, the article explores the contextual needs they were designed to address, and demonstrates how, through team composition and core design principles, as well as through the application of narrative techniques, the worlds described can offer audiences novel ways of considering possible futures.