Grand Admiral Thrawn was tasked to destroy the traitorous Grand Admiral Demetrius Zaarin. To that end Thrawn used Zaarin's desire to get a technological advantage as his weakness. He origanlly had a trap set at the planet Serenity. However Zaarin had learnt it was a trap and sent a small force in response. Thrawn decided set another trap by sending a convoy of genuine Missile Boats to lure him out. However, Thrawn underestimated the amount of Spies in Zaarin's employ and his Task Force Whirlwind was held up in an attack. The attack, although driven off, damaged the Interdictor Whirlwind, leaving only TIE pilot ace Colonel Maarek Stele to defend the convoy.
Stele arrived to find Assault Gunboats preparing to attack the convoy and TIE Defenders fighting the Escort Shuttles. Stele engaged and assited the shuttles in destroying the fighters and as the last few remained Zaarin's Flagship the Imperial I-class Star Destroyer Glory arrived with Carrack-class lifht Cruiser Yaai and EF76 Nebulon-B escort frigate Thinin. Assault Transports, TIE Defenders and TIE Advanced launched from the Glory to attack the convoy so that they could disable and capture it. But Stele attempted to fight them of whenever he could, while inspecting the enemy starships as per orders from the Secret Order. Before any transport could disable and capture the convoy, Thrawn arrived in his Star Destroyer Grey Wolf, along with another Star Destroyer Resolution and two Strike-class medium cruisers. Indomitable and Triumph giving Zaarin's fleet heavy casualties. Because the Whirlwind was not present, Zaarin was able to escape to hyperspace as the remaining starfighters fought and gave their lives.
The battle was undeniably a loss to Zaarin. Losing so many fighters and two medium starships to Thrawn was giving loyalist forces a boost in morale.
With the convoy saved it jumped into hyperspace to a training facility few elite pilots at an undisclosed location. Unfortunately, they didn't arrive and mysteriously disappeared. Worse was that Zaarin had learn't that the Vorknkx Project had just made progress and Zaarin made his next move.
This battle appears in Star Wars: TIE Fighter in Battle 11, Mission 5. This article assumes completion of "Primary", "Secondary" and "Bonus" Goals completed.