Star Wars: The Jedi Academy: Dark Apprentice: Volume 2 (Abridged‪)‬

As the New Republic takes devastating losses in  the ongoingwar with the scattered remnants of the  Empire, the galaxy's future depends on three small  children -- among them the Jedi twins -- born to  incredible powers and perils, as an extraordinary  new saga unfolds...

While the New  Republic struggles to decide what to do with the deadly  Sun Crusher -- a new doomsday weapon stolen from  the Empire by Han Solo -- the renegade Imperial  Admiral Daala uses her fleet of Star Destroyers to  conduct guerrilla warfare on peaceful planets.  And now she threatens the watery homeworld of  Admiral Ackbar. But as the battle for a planet rages,  an even greater danger emerges at Luke  Skywalker's Jedi academy. A brilliant student delves  dangerously into the dark side of the Force and  unleashes the spirit of an ancient master of the evil  order that warped Darth Vader himself. Working  together, they may become an enemy greater than the  New Republic has ever fought... more powerful than  even a Jedi Master can face.