Beginning immediately after Darth Vader confiscated the smuggler's lightsaber and told them that he will not be denied in Episode I, Vader explains that the Smuggler has no choice but to help him capture The Bright Star out of Lady Corvax's secret sanctum, located right underneath Vader's Fortress in Mustafar, and that he senses a latent Force ability within the Smuggler.
Vader decides that he shall train the Smuggler in the ways of the Force, as they will need this knowledge in order to survive the path ahead. The two make their way to the entrance of the inner sanctum, where The Smuggler learns from Vader that their ancestor, Lady Corvax, was force-sensitive during her time. However, Vader explains the Smuggler's ancestor was weak, and broken by her sentimentality and softness, and that the Smuggler will not make the same mistake his ancestor did years ago.
Vader demonstrates the power of the Force on a nearby destroyed statue of Lady Corvax herself, and explains to the Smuggler that the Force is more powerful beyond anything they could ever imagine, as it "discloses the enigmas that will cause the fragile and broken to turn away in horror and agitation" Vader also claims that if the Force is truly someone's servant, they will understand the secrets of life and death both.
As Lady Corvax's machines and devices can only be controlled by her, or her descendants, the Smuggler's bloodline unlocks these devices, but certain other challenges posed by the Force will require additional learning to overcome. Vader initiates the Smuggler's training of the Force by grabbing a nearby activation stone as the Smuggler's first test. The smuggler is instructed to use the Force to take control of the stone, and when they do so, Vader explains that the Force is responding to the Smuggler's bloodline.
Vader then proceeds to place the stone into one of the two pedestals ahead, causing a ceiling key machine to awake as it returns to its proper use. Vader then hands the Smuggler the other activation stone to finish what he started. After the Smuggler does so, the machine releases a pulse of light and opens a gate to another passageway.
Both the Smuggler and Vader move ahead into the passageway, as Vader explains that the Smuggler has still much to learn. Vader engages a second test of the Force, asking the Smuggler to use the Force to defend themselves. After succeeding in the test, the Smuggler learns that they have only viewed a small portion of the Force, but Vader will show them more over time.
The Smuggler then follows Vader who then goes to show them a special blocked message, left to them by Lady Corvax. Corvax tells her descendant to proceed with caution into the area ahead, and reveals how her husband was struck down in battle. She was desperate to save him, which is why she created the Aeon Engine, a device that has the ability to harness the energy and power of the Bright Star. However, her plan failed as Mustafar and the Mustafarians paid a terrible price for her transgressions, leaving the planet the way it is now. Corvax explains that before she passed away, she hid the Bright Star in a hidden chamber near her husband's tomb, as the stone has a chance to unlock a restoration of Mustafar and its people. The message ends by begging her descendant to help.
Vader then explains to the Smuggler that Lady Corvax had absolutely no idea of what she has created, and with the power of the Aeon Engine, the Sith Lord himself will become unstoppable. The two then tread down the pathway and come across a large room populated by nests of Lava nymphs.
Vader then initiates the Smuggler's third test of the Force, to tap into the dark side and exterminate the vermin. The Smuggler does so but is then criticized by Vader as their abilities are acceptable but lacking. He moves towards a central pedestal and watches as a key -- similar to the one given to him by Vader -- shoots out of the pedestal and floats in mid-air. The Smuggler is instructed by the Sith Lord to grab the key with the Force and activate the pedestal. After doing so, a large portion of the floor begins to break apart, but is caught by Vader using the Force. Vader then tells the Smuggler to control his fear.
Before Vader can say anything else, a darkghast attacks the two, forcing him to let go of the Smuggler to fight the creature. The Smuggler falls thousands of feet down into the planet before being knocked unconscious. They witness a vision of the Black Bishop telling him to heed his advice, that Vader must never lay a hand on the Bright Star. Black Bishop explains that he has glimpsed a terrible future as if Vader has the power of the Bright Star, in which hundreds of worlds and galaxies will crumble apart in his grasp, and that the fate of these lost lives are now in the Smuggler's hands. The Black Bishop also explains that the Smuggler must find the Bright Star before Vader does and return it to the Mustafarians, as they can use it to heal the damage done to Mustafar.
After regaining consciousness, the Smuggler is told by Black Bishop that they must climb the caverns to reach his tomb where they can find the Bright Star. But just after, another darkghast attacks them, and the Smuggler is forced to fight the creature as they traverse upward.
- Star Wars: The Lightsaber Collection