The Completionist

Marine Carter Quinn returns home from war just in time for his sister Fred's wedding. There is a fertility crisis in dystopian America; getting pregnant naturally is extremely uncommon now, but Fred, who is marrying into a wealthy family, conceived naturally, subjecting her to strict regulations. She needs the assistant of her sister Gard, a Nurse Completionist, to help her meet the punishing Care Standard requirements during and after her pregnancy. But Gard has gone missing, and Fred asks Carter to find her. However, their father doesn't seem to think it's in Fred's best interest for Gard to be found. After fighting in the multifront war over engineered water, Carter suffers from his own medical issues (PTSD and debilitating headaches), but he soon realizes that his brilliant and strong older sister, Fred, is actually the one in serious trouble.