Complex sentence: Luke and Leia encounter a lake, onto which they must float using a lily pad-like boat; they encounter another creature in the black waters of the underground lake, but Luke makes it go away with his father's lightsaber.
Split into simpler sentences: Luke and Leia encounter a lake, onto which they must float using a lily pad-like boat. They are attacked by a creature in the black waters of the lake, but Luke drives it away with his father's lightsaber.