During the era of the Galactic Civil War, specifically four years prior to the pivotal Battle of Yavin, a minor conflict unfolded at the Garel City Spaceport situated on the planet of Garel. This clash involved rebel operatives and stormtroopers representing the forces of the Galactic Empire. This confrontation was part of a larger operation, spearheaded by the rebel Sabine Wren, with the objective of securing a droid known as EG-86 for the rebellion. Also present was Ketsu Onyo, a Black Sun affiliated bounty hunter with similar intentions regarding the droid. Ultimately, the rebels and Onyo made their escape, and following a temporary alliance between Wren and Onyo, they successfully delivered the droid to R2-D2, who was acting on behalf of Senator Bail Organa at the rebel base of operations called Havoc Outpost.
In the year 4 BBY, Phoenix Leader Hera Syndulla dispatched Sabine Wren, accompanied by Chopper and Ezra Bridger, on a mission to collect a courier who was carrying crucial intelligence for the rebellion. While Hera was unaware of the courier's appearance, she instructed her team that the individual would respond to the coded phrase: "It's a long way to Alderaan." Their task was to rendezvous with the courier at Garel City Spaceport and then transport them to Havoc Outpost, where other members of the rebellion would take custody of the courier.
Unbeknownst to the Spectres, the criminal organization Black Sun had also tasked the bounty hunter Ketsu Onyo with acquiring the courier. Ketsu and Sabine were once friends, with Ketsu having aided Sabine in escaping the Imperial Academy on Mandalore, after which they worked together as bounty hunters. However, Ketsu's "greed" led her to abandon Sabine, leaving her for dead, before joining the Black Sun independently. Sabine was later rescued by the Spectres, who provided her with a fresh start.
Upon their arrival at Garel City Spaceport, Sabine and Ezra began approaching passengers, greeting them with the phrase: "It's a long way to Alderaan." However, they were only met with puzzled looks and shrugs. After the spaceport terminal had emptied, Ezra discovered that the courier was, in fact, a GNK-series power droid identified as EG-86. Before they could proceed with their mission, the three rebels and EG-86 found themselves confronted by Ketsu. Following a tense reunion, Ketsu demanded that the rebels surrender EG-86. Sabine refused, and the two former partners prepared for a gunfight.
Before the confrontation could escalate, a squad of stormtroopers entered the terminal, ordering everyone to surrender. Ketsu responded by firing upon the stormtroopers, initiating a full-blown gun battle. Amidst the chaos, the Spectres and EG-86 managed to board a GX1 short hauler and disable the ship's pilot droid. During the takeoff, Ezra was inadvertently ejected through the side door and left behind.
Simultaneously, Ketsu found herself surrounded by several stormtroopers who demanded she lower her weapons. However, the Mandalorian bounty hunter swiftly dispatched the stormtroopers in hand-to-hand combat. She then retreated by leaping onto a departing shuttle and subsequently onto the roof, where her starship, the Shadow Caster, awaited. Determined to capture the GNK power droid, Ketsu pursued Sabine's ship into space.
Once in the vastness of space, Sabine and Chopper attempted to initiate a jump to hyperspace. However, Ketsu intervened with the Shadow Caster, disabling their shuttle's hyperdrive. She also unleashed fire upon their shuttle, causing damage to the blast door and ejecting Chopper into space. However, Chopper capitalized on this situation by sneaking up behind the Shadow Caster and sabotaging the ship's turret cannon while Ketsu was issuing an ultimatum to Sabine. Ketsu then managed to capture Chopper and offered to negotiate with Sabine.
During the negotiations, Sabine remained steadfast, refusing to abandon her mission, emphasizing her unwavering commitment to the rebellion. Despite their strained relationship, Sabine expressed her willingness to forgive Ketsu. Sabine's dedication to the rebel cause and her forgiving nature resonated with Ketsu, leading to a reconciliation of their friendship. After an Arquitens-class command cruiser appeared, the rebels and Ketsu collaborated to escape by detonating their stolen shuttle. The resulting explosion inflicted significant damage on the Imperial warship. Subsequently, the Spectres, Ketsu, and EG-86 traveled on the Shadow Caster to Havoc Outpost. There, they delivered EG-86 to a group of Alderaanian rebels that included the astromech droid R2-D2.
As a result of her efforts to assist the rebellion, Ketsu not only regained Sabine's friendship but also earned the favor of the rebellion. Later, she provided assistance to the Phoenix Cell by identifying Berzite's moon in the Yost system as a potential location for a rebel base. Following an Imperial attack on Phoenix Squadron, Ketsu aided the rebels by utilizing the Shadow Caster to create a clear path for the Ghost to land on the rebel flagship Phoenix Nest. Unbeknownst to Ketsu, the Empire had orchestrated a trap within the Yost system. However, the rebels managed to evade the trap thanks to the combined efforts of Chopper and the former Imperial inventory droid AP-5.
The Skirmish at Garel was initially depicted in the Star Wars Rebels episode titled "Blood Sisters," which premiered on Disney XD on November 18, 2015. This episode marked the introduction of Ketsu Onyo, voiced by Gina Torres.