The initial assignment of Galen Marek involved a First Mission to the Jedi Temple, designed to finalize his training before he confronted several Jedi.
Following Marek's victory over Rahm Kota during the Battle of the TIE Fighter Construction Facility, Darth Vader dispatched his apprentice to the remains of the Jedi Temple. This was primarily to prepare him for his next mission, as Vader believed Starkiller lacked focus. This lack of focus was evident after Vader's near-fatal test of Marek using Kota's lightsaber.
As the Rogue Shadow landed on the Imperial landing platform, constructed on the entrance staircase of the Temple, the Imperial Navy commandos guarding the entrance tried to order Marek back to the Rogue Shadow. They stated the Jedi Temple was strictly forbidden to outsiders. However, Marek instead defeated the Imperial Stormtroopers on guard. He entered through the damaged Main Hall and battled through more Imperials, including members of the Imperial Senate Sentinels, a unit of the Imperial Senate Guard, to reach a corridor on an upper level. Finding the library entrance sealed, the Sith apprentice retreated to a hallway obstructed by fallen debris.
Marek proceeded down a hallway and entered the mostly undamaged Jedi Trials Chamber. Upon entry, his presence triggered a Jedi training simulation based on the long-deceased Sith Lord, Darth Desolous. The Desolous program, fueled by Marek's fear, initiated an attack with a cortosis shield and a red lightsaber.
Marek defended against the hologram's lightsaber attacks and used Force lightning to stagger the program. Although the Desolous program replicated the original Sith Lord's considerable Force abilities, it was unable to match the raw power of Vader's apprentice. Marek hurled pieces of the surrounding statues at his opponent, eventually weakening the avatar's defenses.
The Desolous program, nearing defeat, attempted a final attack on Marek, but failed. Marek then used the Force to launch Desolous's hologram toward the main statue at the top of the hall, up along the statue's surface. The program was then thrown down from the statue's face and slammed into the stone floor. With a final Force pull, the main statue collapsed onto the hologram of the ancient Sith Lord, defeating it and ending the Trials program.
PROXY, Marek's holodroid companion, entered the room immediately after the training program concluded. Confused by PROXY's presence, Marek watched as PROXY's holodroid functions transformed him into Darth Vader, causing Marek to kneel automatically. Vader then informed him that his spies had located the Jedi Master Kazdan Paratus. Vader expressed doubt in Starkiller's ability to defeat Paratus, but stated that success would bring him closer to his destiny of assassinating Emperor Palpatine. Marek, vowing not to fail his master, departed the Temple to hunt for Paratus.
This particular mission is exclusively available in the PlayStation 2, PlayStation Portable, and Wii versions of The Force Unleashed. In the Xbox 360 and PlayStation 3 versions, Starkiller proceeds directly to Raxus Prime after the TIE Fighter Construction Facility.