Excalibur

The alien menace that nearly wiped out all life in allied space has returned, and only disgraced Captain Marek Albion knows it. He and the crew of the Excalibur, an older generation alien craft found abandoned in an asteroid field, stumble across a plot by the bugs to seek vengeance for their earlier defeat. With no help from the military, Albion must track down the invaders and stop them before their destructive plan hatches and plunges all of humanity into a war it cannot win.