Nightmare Squadron was a unit of Rebel Alliance T-65B X-wing starfighters deployed to Titan Base, a subterranean starfighter facility in the Corva Sector. By 0 ABY, the squadron was conducting operations mainly in nearby sectors and had developed a reputation for lightning-fast, destructive raids on Imperial targets. At the time of the arrival of an Alliance Special Operations team for a mission to disrupt the Empire's Operation: Shell-cracker, the squadron was preparing for what its commander Jayce Terril called an ambush double, where they can execute a micro-jump to another location. Shortly afterward, the squadron hyperspaced to The Hammer to assist the team in stealing the Shell-cracker prototype and battled Alpha Squadron.