The Grills Quadrant lies in the Enigma Sector and consists of the Axius, Cabrea, Callimachus, Cardell, Fiddler's Green, Heaven's Gate, Hillerman, Irving, Niffleheim, Novaya Kiev, Pembroke, Speradon, Talbot and Vespus systems.
The Grills Quadrant was the site of much conflict during the Terran-Kilrathi War, and hosted many critical battles of the decisive Enigma Sector Campaign:
- The Kilrathi retreat to Novaya Kiev after a failed offensive on Ghorah Khar in 2667. The enemy force is pursued by the TCS Concordia, resulting in heavy losses to the Kilrathi.
- The Terrans launch a major offensive to liberate Heaven's Gate from the Kilrathi in 2667; The offensive is aborted when a traitor aboard the Concordia alerts the Kilrathi, prompting a major strike in which the Terrans destroy the Heaven's Gate Starbase due to the sacrifice of pilot Mariko Tanaka.
- The Kilrathi occupy Niffleheim in 2666; the planet is eventually liberated by Confederation Space Marines in 2667.
- The Kilrathi stage a major offensive to occupy Pembroke after the Terrans liberated the Enigma Sector in 2667. A massive strike against Pembroke Station fails due to the intervention of the TCS Concordia.
- The Concordia is intercepted and destroyed by the Kilrathi and crashlands on Vespus in 2669; the flagship is declared a total loss.
- The Terrans successfully liberate Gardel in 2669.
- After an indeterminate period of occupation, the Terrans liberate Cabrea in 2669; all communications with the colony are restricted in the wake of the horrifying conditions discovered on the planet.
- After the Terran-Kilrathi War, the secretive Black Lance establishes its main base of operations in the unpopulated Axius System.
- The Union of Border Worlds launch a major offensive to seize Confederation war materials in Speradon during the Border Worlds Conflict in 2673; the unfinished TCS Princeton is captured by the BWS Intrepid and BWS John Hopkins.
- The Intrepid arrives in Callimachus in 2673; its acting captain Christopher Blair launches to investigate enemy activity in the neighboring Axius System.
- Colonel Christopher Blair infiltrates Axius Starbase, discovering the Black Lance and its leader Admiral Geoffrey Tolwyn to be the true instigators of the ongoing conflict.