Countless star systems fell to the Empire during the Great War, yet many in the Republic believed the Core Worlds were safe from attack. That all changed when the Empire invaded Alderaan; the Sith Lord Darth Malgus led the attack, timing his invasion with a feint that drew the Republic's fleet light years away.
Unknown to Malgus, a small contingent of Republic soldiers was stationed on Alderaan. The soldiers were outnumbered and disorganized, but among them were the members of Havoc Squad, the Republic's most decorated military unit. Under the leadership of Captain Jace Malcom, the Havoc Squad commandos rallied the Republic troops and waged a fierce guerrilla campaign against the Empire.
The resistance fighters harried the Imperial forces constantly, delaying their advance long enough for the Republic fleet to race back and repel the invasion. In the end, Darth Malgus was defeated and the Empire was driven from Alderaan. The victory was a costly one, though; Alderaan would not soon forget the devastation.