Still haunted by the events in Revenge of the Sith, Darth Vader must set aside his past and put his future on hold for a mission to the mysterious Ghost Nebula to locate-and if possible, rescue-a missing Imperial expeditionary force. But what seems a perfect opportunity to lose himself in his duty is complicated by two factors: he is paired with a willful yet highly competent co-commander, and the officer they are being sent to locate is the son of Vader's rising nemesis, Moff Tarkin.