The Third Recon Group functioned as a military reconnaissance regiment within the structure of the New Republic Defense Force. This particular unit saw action during the Battle of Jakku, which marked the concluding engagement of the Galactic Civil War fought between the New Republic and the Galactic Empire. During this significant battle, Major Ranz held the position of group commander, and the group's mission was to neutralize an Imperial supply convoy that was on its way to reinforce Imperial ground troops, an action that would have prolonged the conflict. While striving to achieve their assigned objective, Third Recon Group encountered two downed New Republic pilots, specifically Gina Moonsong and Temmin Wexley.
The Third Recon Group was a reconnaissance regiment serving under the New Republic Defense Force. Major Ranz held the leadership position as group commander. Before the Battle of Jakku, the group consisted of a full company of New Republic soldiers, including the group command element and a squad directly reporting to Major Ranz. Sergeant Agarne was also a member of Third Recon Group. The group's equipment included blaster rifles, explosive power packs, rockets, anti-personnel grenades, and various communication devices.

In 5 ABY, after substantial numbers of loyalist Galactic Empire forces were discovered on Jakku, and following the New Republic Senate's authorization to intervene, the New Republic Defense Fleet launched an assault on the Western Reaches planet and the Imperial forces stationed there, thereby initiating the Battle of Jakku. Major Ranz's Third Recon Group was deployed onto Jakku's surface with the specific mission of destroying a heavily armored Imperial supply convoy. This convoy was intended to reinforce Imperial positions located at Golga Station. Having successfully infiltrated 100 kilometers behind Imperial lines, and with thousands of Imperial ground forces situated between their position and Base Alpha, Third Recon Group's strength had dwindled from a full company to only a dozen soldiers by the day preceding the planned ambush. Approximately thirty minutes before they were scheduled to ambush the convoy, six soldiers from Third Recon Group, including Sergeant Agarne, encountered Lieutenant Gina Moonsong of Blade Squadron and Temmin Wexley of Phantom Squadron, both of whom were New Republic pilots.
Sergeant Agarne initiated the exchange by reciting the challenge code, to which Moonsong responded with "Thunder," and Agarne confirmed with "Lightning." Agarne introduced himself and then escorted the pilots across several sand dunes to the location of group command, which was positioned within a trench. Following introductions, Moonsong requested a comlink from Ranz, but this request was denied because Third Recon Group was under orders to maintain strict radio silence until they engaged their designated enemy objective. Ranz further explained that excessive electromagnetic interference made any attempt to contact other forces futile. Subsequently, Ranz briefed Moonsong and Wexley on their mission: they were anticipating a reinforced stormtrooper company assigned to protect the supply convoy, which consisted of six K79-S80 Imperial Troop Transports and would be traveling through a specific pass. Moonsong successfully persuaded Ranz that they were authorized to break radio silence once contact with the enemy was established.
By this point in time, a significant number of the remaining soldiers, nearly a dozen, had sustained injuries. Eventually, the convoy proceeded into the pass, and the New Republic forces launched their ambush after receiving the order from Ranz. The scouts detonated rigged power packs that they had buried in the sand, resulting in the destruction of the second transport in the convoy. The third transport subsequently collided with the wreckage, while the remaining troop transports established a triangular defensive perimeter and opened fire on the New Republic forces. Ranz and the troopers emerged from their concealed positions and targeted the rear of the ITTs with rockets, effectively destroying the back sections of the transports and eliminating stormtroopers who had not yet disembarked. However, the remaining stormtroopers quickly regrouped, formed a skirmish line, and returned fire. The Imperials also deployed a heavy weapons team that encountered difficulties in setting up their position, while stormtroopers from the front of the convoy moved towards the rear to reinforce it.

At that crucial moment, Ranz instructed the two Republic pilots and three troopers to initiate an attack from the front, employing anti-personnel grenades and directing fire at the command ITT. Moonsong gained entry into the transport to access its communication equipment and directed Wexley to realign the damaged communications dish. Moonsong then successfully contacted New Republic Starfighter Command, establishing communication with Fleet Admiral Gial Ackbar's command ship, the Home One. By this stage, Third Recon Group's soldiers were being overwhelmed by the Imperial forces, with the heavy weapons team targeting New Republic positions and stormtroopers executing flanking maneuvers. Suddenly, a significant explosion occurred in the area where Major Ranz and his soldiers were located. Moonsong concluded that Ranz must have detonated the remaining explosives to prevent the Imperial troops from overrunning his position. A few of the surviving New Republic troopers who had participated in the attack on the front of the convoy retreated to Moonsong's location.
With their ammunition dwindling, the New Republic forces came under attack from TIE fighters in the air, which resulted in the elimination of the majority of Ranz's troops, as well as several stormtroopers who were positioned too close to the New Republic soldiers. At that point, the Third Recon Group soldiers near Moonsong believed that their survival was unlikely and that surrender was imminent. However, at that precise moment, A/SF-01 B-wing starfighters from Moonsong's Blade Squadron arrived and destroyed the TIE fighters. They then turned their attention to the dispersing Imperial ground troops, firing upon them as they retreated, thereby eliminating the majority of the Imperial forces. Subsequently, the squadron landed around the secured battlefield, effectively completing Third Recon Group's objective.
Third Recon Group was featured in the short story titled "Blade Squadron: Jakku," authored by David J. Williams and Mark S. Williams. It was released on April 12, 2017 and published in Star Wars Insider 172 as a tie-in to Aftermath: Empire's End, a novel written by Chuck Wendig that concluded Star Wars: The Aftermath Trilogy.