'Star Wars: Darth Vader and the Ghost Prison' is a comic book - or "Graphic Novel" as the hip, young Padawans call it - in the extended Star Wars universe.
"A traitorous uprising against the fledgling Galactic Empire leaves Emperor Palpatine close to death. Saving the Emperor—and the Empire—appears to be a lost cause … unless Vader can uncover the secrets of the Jedi Council and locate the mysterious “Ghost Prison.” Collects the five-issue miniseries."
A summary written by the author, Haden Blackman, of 'The Force Unleashed' fame.
This issue does not appear to be in the AU marketplace.