The privilege of peace - Tanya Huff

Former space marine Torin Kerr returns for one final adventure to save the Confederation in the last book in the military science fiction Peacekeeper trilogy.

Warden Torin Kerr has put her past behind her and built a life away from the war and everything that meant. From the good, from the bad. From the heroics, from the betrayal. She's created a place and purpose for others like her, a way to use their training for the good of the Confederation. She has friends, family, purpose.

Unfortunately, her past refuses to grant her the same absolution. Big Yellow, the ship form of the plastic aliens responsible for the war, returns. The Silsviss test the strength of the Confederation. Torin has to be Gunnery Sergeant Kerr once again and find a way to keep the peace.