During the Clone Wars, the Galactic Republic annexed the Twi'lek homeworld of Ryloth after liberating it from the Separatists. The Republic was succeeded by the Galactic Empire, which established a protectorate over Ryloth. The Empire sought to exploit Ryloth for its spice resources. While the planet was nominally independent and represented in the Imperial Senate by Senator Orn Free Taa, real power lay in the hands of the Imperial governor Moff Delian Mors and her subordinate Colonel Belkor Dray.
By 14 BBY, an active insurgent movement known as the Free Ryloth Movement had emerged on Ryloth under the leadership of Cham Syndulla, a veteran of the Clone Wars. Cham fought to free Ryloth from Imperial rule. He recruited and trained hundreds of rebel fighters and established a network of informants and contacts across the Ryloth system. The Free Ryloth movement staged attacks on Imperial personnel and disrupted the planet's spice trade. Cham was assisted by Belkor Dray, who resented Moff Mors' decadent lifestyle and wanted to discredit her. He became an important spy for the Free Ryloth movement.
In 14 BBY, Cham's lieutenant Pok hijacked an Imperial weapons shipment at the Yaga Minor shipyards and fled into hyperspace. Pok planned to rendezvous with Cham and Isval's ship in the rings of a gas giant in an off-chart system. To avoid detection, Pok and his crew kept silent over the com. On the way, they skimmed a gas giant to refuel. While waiting, Isval sighted Pok's stolen transport. The transport began hailing Cham's ship and he ordered his crew to aleart the offload team, get the weapons aboard, and destroy the transport.
Darth Vader (pictured) pursued the Free Ryloth Movement
Before they could dock with Pok's transport, Cham received a frantic message from Pok that they were being pursued by Darth Vader's personal Eta-2 Actis-class light interceptor and several V-wing starfighters. Pok had made several hyperspace jumps in an attempt to lose the Imperials but had failed to shake off Vader and his squadron, whose fighters were equipped with hyperspace transport rings.
One of the hijacked transport's engines broke down due to the strains of the pursuit. Vader ordered his V-wing pilots to disable the ship's deflector shields and the remaining two engines in order to prevent it from jumping into hyperspace again. The Twi'lek rebels fought back with the ship's armaments and managed to shoot down two of the Imperial V-wings. The remaining V-wings attacked the transport from multiple angles and managed to weaken the shields and knock out another engine. The squadron commander split the squadron and ordered his fighters to circle the ship until they had knocked out the shields.
Meanwhile, Cham offered to help Pok but Pok refused. He explained that they were already down to one engine and that there was a Star Destroyer behind them. Though Isval urged Cham to helped Pok, Cham decided not to intervene in order not to expose their position behind the ring. After the Imperials had disabled the transport's shields, Vader ordered them to take out the engines and to destroy the ship's turrets and starboard-side midline gun bubble. The squadron leader then recommended leaving the ship stranded in space until Vader's Star Destroyer Perilous to tow it into its cargo bay.
However, Vader had no intention of letting the crew live and intended to board the transport. Though the squadron commander pointed out that the ship's docking clamp was damaged and that it had no landing bay, Vader was unperturbed. He used the Force to ram his light interceptor into the remaining gun bubble before ejecting into space. This caused the hijacked transport to lurch. Vader contacted the squadron commander via his helmet comm and informed him that he was docking with the transport. He also instructed the crew to remain on comm silence and to escort the stricken freighter until the Perilous arrived.
Once aboard, Vader used his knowledge of override codes to enter the ship's corridors. He killed the Twi'lek man Tymo with his lightsaber before the latter could shoot him with his blaster. Taking Tymo's comlink, he informed the rest of the crew he was coming for them. With the ship's engines and defenses destroyed, Pok and his 26 crew decided to make their way to the cargo hold and use their weapons as a fail-safe to fight Darth Vader. Pok was willing to die for a free Ryloth. Isvak wanted to help Pok but Cham countered that Pok's team were "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 and killed the eight rebels guarding the turbolift. Vader fought 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 death of Pok and his team, Cham and his crew took their ship deeper into the rings. They hid 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 survived the collision intact. After the Imperials had passed, Cham ordered his crew to power up their ships. Since they had failed to obtain the weapons shipment, Cham ordered his crew to return to Ryloth. He vowed that they would use "no more half measures" and that they would "think bigger."
After returning to Coruscant, Vader and the Emperor deduced 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 the Yaga Minor weapons shipment. To lure the rebels out of hiding, Palpatine planned to travel to Ryloth with Senator Free Taa aboard the Perilous. Through a spy in the Senator's staff, Cham Syndulla learned about the trip and mounted a daring attempt to overthrow the Emperor.
The mission to hijack an Imperial weapons shipment first appeared as the exposition to Paul S. Kemp's 2015 novel Lords of the Sith.
- Star Wars Encyclopedia of Starfighters and Other Vehicles