Subsequently, Yoda battles Sidious in a lightsaber duel that damages the Senate Rotunda. In the end, neither is able to overcome the other and Yoda is forced to retreat. He goes into exile on Dagobah so that he may hide from the Empire and wait for another opportunity to destroy the Sith. At the end of the film, it is revealed that Yoda has been in contact with Qui-Gon's spirit, learning the secret of immortality from him and passing it on to Obi-Wan.