Over a year prior to the attack, in 19 BBY, Clone Captain Howzer, who was stationed on Ryloth in a squad a part of a larger battalion, defied the Galactic Empire and encouraged his fellow troopers to stand with him. Though a portion of his squad stood with him, Howzer and his rebellious squad mates were immediately arrested and taken into Imperial custody. Over the course of more than a year, six of the eight members of Howzer's squad who stood with him would die in Imperial captivity. Eventually, Howzer and his surviving men would be chosen to be sent to an Imperial facility on the planet of Wayland. After being escorted on to a Gozanti-class cruiser by TK stormtroopers and a clone commando, the ship would depart for Wayland.
Shortly after departing for Wayland, the Imperial ship was ambushed by a ship belonging to rogue Clone Captain Rex's resistance network, who were tipped off about the shipment by a contact from within the Empire. Unable to jump to hyperspace due to damage sustained in the sudden ambush, Captain Pearce ordered the ship's pilots to return fire and notify Imperial command for backup. Realizing that they were short on time, the rogue clones Echo, Fireball, and Nemec quickly boarded the Imperial shuttle using a leech vessel. Meanwhile, Pearce ordered his TK stormtrooper to prepare to be boarded, and a fierce firefight ensued between the Imperial forces and rogue clones. As the ship's stormtroopers were quickly overwhelmed, Pearce ordered an Imperial clone commando to erase the ship's databank to prevent its information from falling into the rogue clones' possession. Echo and Nemec would quickly reach the bridge and dispatch the commando before this could be completed, and held Pearce at gunpoint. As Echo attempted to retrieve what data remained, Nemec demanded Pearce to tell him where the ship's prisoners were being taken. Instead, Pearce bit down on a suicide shocker, killing himself instantly.
Shortly after, an Imperial Venator-class Star Destroyer dropped out of hyperspace in response to the Gozanti's distress signal, and deployed a squadron of Alpha-3 Nimbus-class V-wing starfighters. As Echo, Nemec, Fireball, and the rescued prisoners fled the ship, the Imperial starfighters strafed and destroyed the Gozanti-class cruiser. Before they could be targeted next, the rogue clones jumped to hyperspace and escaped.