A detailed Traveller sector book covering all of the Reaver's Deep subsectors and several important worlds of the sector.
From the back of the book:
The Reaver's Deep sector borders on the rimward edge of the Imperium adjacent to the Great Rift, and has been a buffer zone for its larger galactic neighbors throughout known history. Hundreds of unallied worlds and a handful of pocket interstellar states comprise the sector. This structure keeps Reaver's Deep sectors' geopolitical character in constant turmoil, as petty wars rage, alliances shift, trade routes are created, destroyed, or simply altered, and cultures rise and fall.