On Cygnus, a moon of exoplanet 16 Cygni Bb, long icy winters give way to summers hot enough to melt lead. For 365 years, Cygnus has fallen short of its founders' vision of a crucible for a new humanity. Interstellar travel has withered. Corruption, stagnation and violence have left Cygnus teetering on the brink of collapse. This Winter's End, the vestiges of hope survive in the darkest places. An inventor lies dead in an icy alleyway. In the right hands, his prototype has the power to transform Cygnus, and perhaps save it... but whose hands are those? Cygnan Power Corporation, which has sustained - or corrupted - Cygnus for three centuries? The rebel Peng-lai movement, which aims to restore Cygnus to its founding ideals? Fixer Jimmy Fergus, who wants the prototype for himself and is willing to fan the flames of revolution to obtain it? Officer Deepankar Varanasi vows to thwart Jimmy Fergus and the rebels. Can he keep the fabric of Cygnus from unraveling before his world goes up in flames? Warming Season is the first book in the Cygnus series, which takes place within the Cygnus universe, first introduced in the short stories "In Cygnus and in Hell" and "Home Cygnus," published in the journal Nature. The short stories followed Dorothy Fenton's journey to Cygnus on the Xi-Zhong colony ship. The Cygnus series reveals the end result of that journey and the fate of the Xi-Zhong mission. Warming Season sets the stage for the fall of the Cygnus colony... or perhaps its rise, or the genesis of something new.