A unit of stormtroopers and clone troopers, led by Clone Captain Wilco, received orders to retrieve Count Dooku's war chest from Castle Serenno. This castle was located on the planet also called Serenno. During this operation, the company became the target of a raid executed by the rogue Clone Force 99, also known as the "Bad Batch."
This military group consisted of at least forty stormtroopers and clone troopers, all under the command of Clone Captain Wilco. The troopers had standard Phase II clone trooper armor and DC-15A blaster carbines. Captain Wilco wore a black shoulder pauldron to visually represent his command rank. The clones utilized Alpha-3 Nimbus-class V-wing starfighter, BARC speeders, LAAT/i gunships, and at least three class four container transports.
Following the end of the Clone Wars and the formation of the Galactic Empire, Captain Wilco and his unit were stationed on Serenno, formerly a Separatist world. Some months after the war's conclusion, Wilco's focus shifted to the remnants of Castle Serenno, the former residence of Separatist leader Count Dooku.
Wilco and his troops received the assignment of extracting Dooku's war chest from the destroyed palace. The treasure was placed inside large shipping containers and loaded onto three class four container transports for off-world transport. Clone Force 99, taking on a mission from Ciddarin Scaleback, infiltrated the palace's shipyard to steal some of Dooku's war chest. However, they were quickly discovered, resulting in a intense firefight with the clone stormtroopers. While half of the rogue clone squad managed to board one of the class four container transports, Wrecker and Hunter were forced to remain behind.
The two rogue commandos then infiltrated Dooku's palace, but Wilco and his troops spotted them again. Nevertheless, the two clones were able to escape through a hidden passage behind Dooku's personal desk. Meanwhile, Tech, Echo, and Omega found themselves on the hijacked transport shuttle, where they engaged in combat with the ship's stormtrooper crew and attempted to flee using the ship's escape pods. However, Captain Wilco ordered the shuttle's pilots to quickly jettison the escape pods. The group then came up with a plan to escape using a cargo container, since it was equipped with reentry thrusters that would ensure a safe descent. Executing their plan, the rogue clones successfully escaped the shuttle while also releasing the remainder of the ship's cargo, scattering it across the surface of Serenno.
Captain Wilco split his forces to continue the pursuit of the thieves. A small group of troopers was dispatched to locate the cargo container team. The majority of his forces, meanwhile, followed Hunter and Wrecker into the ruins of the Serennian City. Wilco and his stormtroopers were able to corner Hunter and Wrecker, prompting Wilco to request aerial support. However, just as a V-wing starfighter reached their position, Wrecker tore off and activated a cannon from a destroyed Separatist tank, using it to shoot down the V-wing. Wrecker then bombarded Wilco and his stormtroopers, causing them to retreat in disarray. Hunter and Wrecker were able to reach their ship, the Marauder, and escape.
At the same time, a squad of clone stormtroopers on BARC speeders located the container where Tech, Echo, and Omega had landed. The troopers had pinned Echo and Omega inside the container, when Tech suddenly ambushed them. Despite being injured, Tech emerged victorious after a fierce firefight with the clones. As Tech attempted to help his squad mates out of the container, he spotted an LAAT/i gunship approaching their location. Using a mounted gun, he shot down the gunship, causing it to crash into the mountainside. Tech quickly shot down two more clone stormtroopers who had arrived on BARC speeders before successfully extracting his team. Wrecker and Hunter arrived in the Marauder, and the squad escaped Serenno.
Following these events, Captain Wilco reported back to Vice Admiral Edmon Rampart at the castle, detailing the process of securing the lost cargo and the appearance of the Bad Batch. Rampart, concerned about the survival of the rogue clones (who were believed to have died on Kamino during the aerial bombardment of Tipoca City), ordered Wilco to falsify his report to prevent Rampart from losing favor with his superior, Governor Wilhuff Tarkin. When Wilco refused to alter an official report, Rampart executed him and promised to write his own version.