In the add-on’s plot, the Tiger’s Claw, on maneuvers in the Goddard System, receives an abortive distress call from Goddard colony. When the Claw arrives, though, nothing is left but wreckage and corpses; a quarter of a million colonists have been killed. Confed realizes that this is the work of a new Kilrathi weapon, the “Graviton weapon”, which is able to increase the power of gravity by over a hundred times.
Clever work by the Claw’s crew and pilots allows them to capture a Kilrathi courier ship, which reveals that this weapon is mounted on an entirely new class of ship; CNC codenames it the Sivar-class dreadnought, after the Kilrathi god of war. Bluehair leads the strike against the Sivar and destroys it in the Vigrid system; for unexplained reasons, ships of that class and armament are never seen again.