The Lost Fleet: Relentless

Captain John "Black Jack" Geary races to save a group of Alliance POWs from certain death in this gripping novel in New York Times bestselling author Jack Campbell's Lost Fleet series.   Alliance prisoners of war are being held at a labor camp in the Heradao star system, which also happens to be the location of the majority of the surviving Syndic warships. Determined not to leave any of his people behind, "Black Jack" Geary orders the fleet to strike hard and fast to rescue the POWs with minimal Alliance losses.
  The raid is successful, but victory is short-lived. Geary discovers that the Syndics plan to ambush the fleet with their powerful reserve flotilla in an attempt to annihilate it once and for all-but he doesn't know where the enemy is located. And as Geary has the fleet jump from one star system to the next, hoping to avoid the inevitable confrontation, saboteurs contribute to the chaos...