Far in the future, an alliance of peaceful alien species known as the Confederation is locked in a continuous battle with the hostile Others, and it's up to humanity to protect them. Gunnery Sergeant Torin Kerr has been declared missing, presumed dead. But, unknown to the rest of the Confederation marines, she has been sent to an underground prisoner of war camp, alongside several one-time enemies. Whilst trying to save herself and her new comrades, Torin makes a discovery that could shake the Confederation to its core, and bring an end to the war with the Others forever.