A duel took a place in 3 ABY in the Dark Side Cave on the planet Dagobah, between Luke Skywalker and the Dark Spirit, who had assumed the shape of Darth Vader. It was a part of Skywalker's Jedi training and occurred because his Jedi Master Yoda had asked him to enter the cave so he could face his darkest fears. Beforehand, when Skywalker inquired whether there was anything that posed as a threat, Yoda cryptically replied that the only thing to threaten him was "what [Skywalker] carried in with him," and also advised that Skywalker not bring his weaponry inside as he won't need them. Skywalker seemingly got the upper hand, beheading the apparition. However, when the fake Vader's helmeted head hit the ground, its mask exploded, revealing the face of Skywalker himself.
- Star Wars Episode V: The Empire Strikes Back novel (First appearance)
- Star Wars Episode V: The Empire Strikes Back junior novel
- Star Wars: Episode V The Empire Strikes Back