The Third Imperium has fought four Frontier Wars against the Zhodani Consulate and its allies. Worlds have changed hands, borders have been readjusted, but never has the Imperium been seriously threatened until now. As Zhodani battle fleets emerge from jumpspace at Regina, Efate, and Jewell, something is different this time. The Imperials are divided, arguing over who should be Sector Duke even as raiders tear through the Lunion and Glisten subsectors. Lanth is under ground attack. Extolay is burning. The Imperial response is fragmented and ineffective. Reinforcements are months away and the Sector Admiral is frittering away what forces he has. Hold back the Zhodani tide at the First Battle of Regina or lead the breakthrough of the 40th Fleet as it lunges at Macene. These are the great events that will shape the future, and it may be that the outcome rests on the actions of your Travellers. The Fifth Frontier War is the first sourcebook in this massive campaign that can span years of play and will powerfully alter the future of the Charted Space universe.