In 14 BBY, a mission was launched by several members of the Free Ryloth Movement, led by Pok. The objective was to seize control of an Imperial weapons consignment located at the Yaga Minor shipyards. They successfully transferred the armaments onto a freighter and aimed to link up with another Free Ryloth starship, under the command of Cham Syndulla and Isval. Despite executing multiple hyperspace jumps to evade the pursuing Imperials, Darth Vader managed to infiltrate their freighter. Subsequently, he personally killed Pok's entire team. Cham and Isval overheard the complete slaughter through the comms and pledged to escalate their rebellion against the Empire.
During the era of the Clone Wars, the Galactic Republic incorporated the Twi'lek home planet of Ryloth after liberating it from the control of the Separatists. The Galactic Empire succeeded the Republic, establishing a protectorate over Ryloth. The Empire's intention was to exploit Ryloth for its spice resources. While Senator Orn Free Taa represented the planet in the Imperial Senate, the true authority rested with the Imperial governor, Moff Delian Mors, and her subordinate Colonel Belkor Dray.
By the year 14 BBY, an insurgent group, known as the Free Ryloth Movement, had formed on Ryloth. It was spearheaded by Cham Syndulla, a Clone Wars veteran, who fought for Ryloth's liberation from Imperial dominion. He enlisted and trained numerous rebel soldiers, creating a network of informants and contacts across the Ryloth system. The Free Ryloth Movement launched attacks on Imperial personnel and disrupted the planet's spice trade. Cham received assistance from Belkor Dray, who, disliking Moff Mors' opulent lifestyle, aimed to discredit her and became a valuable spy for the Free Ryloth Movement.
In 14 BBY, Pok, Cham's lieutenant, commandeered an Imperial weapons shipment at the Yaga Minor shipyards and made a hyperspace jump to escape. Pok's plan was to meet up with Cham and Isval's vessel within the rings of a gas giant in an uncharted system. Pok and his crew maintained radio silence to avoid detection. En route, they skimmed a gas giant to refuel. While they were waiting, Isval spotted Pok's stolen transport. The transport then began hailing Cham's ship, prompting him to instruct his crew to alert the offload team, bring the weapons onboard, and destroy the transport.
Before they could dock with Pok's transport, Cham received a frantic message from Pok, stating that they were being pursued by Darth Vader's personal Eta-2 Actis-class light interceptor and a number of V-wing starfighters. Pok had made several hyperspace jumps hoping to outpace the Imperials, but he was unable to shake off Vader and his squadron. Vader's fighters were equipped with hyperspace transport rings.
Due to the strain of the pursuit, one of the hijacked transport's engines failed. Vader commanded his V-wing pilots to disable the ship's deflector shields and the remaining two engines to prevent another hyperspace jump. The Twi'lek rebels retaliated with the ship's weaponry, successfully shooting down two Imperial V-wings. The remaining V-wings attacked from multiple angles, weakening the shields and disabling another engine. The squadron commander divided the squadron, ordering his fighters to circle the ship until the shields were down.
Meanwhile, Cham offered assistance to Pok, but Pok declined. He explained that they were down to one engine and that a Star Destroyer was behind them. Despite Isval's urging, Cham decided not to intervene to avoid revealing their position behind the ring. After the Imperials disabled the transport's shields, Vader instructed them to take out the engines and destroy the ship's turrets and starboard-side midline gun bubble. The squadron leader then suggested leaving the ship stranded in space until Vader's Star Destroyer, the Perilous, could tow it into its cargo bay.
However, Vader intended to board the transport and eliminate the crew. Despite the squadron commander pointing out the damaged docking clamp and the absence of a landing bay, Vader was undeterred. He used the Force to crash his light interceptor into the remaining gun bubble before ejecting into space, causing the hijacked transport to lurch. Vader contacted the squadron commander via his helmet comm, informing him of his docking with the transport. He instructed the crew to maintain radio silence and escort the stricken freighter until the Perilous arrived.
Once aboard, Vader used his knowledge of override codes to gain access to the ship's corridors. He eliminated the Twi'lek man Tymo with his lightsaber before Tymo could shoot him with his blaster. Using Tymo's comlink, he announced his approach to the rest of the crew. With the ship's engines and defenses destroyed, Pok and his 26 crew members decided to head to the cargo hold, using their weapons as a last resort to fight Darth Vader. Pok was willing to sacrifice himself for a free Ryloth. Isvak wanted to aid Pok, but Cham argued that Pok's team was "dead in space."
Vader killed the team that Pok had sent to the hold. After wishing Cham and Isval farewell, Pok commenced with his plan to ambush Vader. Vader fought his way to the bridge, killing the eight rebels guarding the turbolift. Vader forced his way into the bridge and attacked Pok and his remaining crew. Following a brief battle, Vader killed Pok's remaining men and proceeded to Force choke the rebel leader. Vader demanded that Pok tell him what he wanted to know, but Pok cursed him in Twi'leki. Vader then broke Pok's neck. Cham and Isval heard the battle and Pok's last moments on the com. Vader then announced that Cham's allies were dead before Cham switched off the com.
Following the demise of Pok and his team, Cham and his crew maneuvered their ship deeper into the rings, hiding while Vader's V-wings searched the area for other rebel ships. To avoid detection, Cham reduced life support to the minimum. Cham's ship collided with a rock but sustained no critical damage. Once the Imperials had passed, Cham ordered his crew to power up their ships. Having failed to acquire the weapons shipment, Cham ordered his crew to return to Ryloth, vowing to employ "no more half measures" and to "think bigger."
Upon returning to Coruscant, Vader and the Emperor concluded that a spy within either Senator Orn Free Taa's staff or the Imperial government had been leaking information to the Free Ryloth Movement, including details of the Yaga Minor weapons shipment. To draw the rebels out, Palpatine planned to travel to Ryloth with Senator Free Taa aboard the Perilous. Through a spy in the Senator's staff, Cham Syndulla learned of the trip and launched a daring attempt to overthrow the Emperor.
The mission to hijack an Imperial weapons shipment was initially introduced as the exposition in Paul S. Kemp's 2015 novel, Lords of the Sith. The mission was visually depicted for the first time in the Lords of the Sith manga adaptation within Star Wars Rebels, Vol. 1.