From publisher blurb: Under Alien Skies expands the setting of Trinity Continuum: Aeon with details about the alien Chromatics, Coalition, and Listeners, including rules for playing characters belonging to these three species. In addition, this book provides information about six other species of aliens. Inside, you will find: Further information about the Chromatics, Coalition, and Listeners, including details about their lives and societies, rules for creating characters belonging to these species, and advice to Storyguides for incorporating these aliens into their chronicles. Information on five extinct or nearly extinct aliens, including several that left behind dire threats to humanity, as well as the first detailed information about the strange and malevolent Doyen. Advice to Storyguides for incorporating aliens into their campaigns as either species for the characters to encounter and as characters who are the heroines and heroes of their own chronicles. Step by step instructions for creating new aliens species as either creatures for characters to encounter as well as unusual options for characters. New technologies used by various aliens, including common devices and barely understood wonders that continue to baffle and amaze human researchers.