Three years after the destruction of the Death Star, the Rebel Alliance continues the fight against the Imperial forces and suffers a defeat on the ice planet Hoth. Luke Skywalker journeys to the planet Dagobah to train with Jedi Master Yoda, who has lived in hiding since the fall of the Republic. In an attempt to convert Luke to the dark side, the evil Sith Lord, Darth Vader, lures Luke into a trap in the Cloud City of Bespin. In the midst of a fierce lightsaber duel with Vader, Luke faces the startling revelation that the Sith lord is in fact his father, Anakin Skywalker.
Developed for service aboard capital warships and battle stations, these droids look much like R2 units except for their clear plastex domes that show off their computer processors.