The title is the name of a woman without direction. Leavey is treated poorly by her mother and step-father in a small New York town. She has no where to go. She's going there fast, fueled by drugs and alcohol. She joins the Marines to get out of town.
Once in the corps, even as she trains, Leavey continues making poor decisions. As punishment, she is sent to the kennels to clean dog poop. The German shepherds are being trained to be soldiers as well, soldiers who sniff out bombs. She's not very good at first. She seems to have no more connection with canines than she does with humans.
She is granted the right to handle Rex after the dog bites his first handler. And Leavey begins to connect. When Rex barks constantly on the transport to Camp Ramadi in Iraw, Leavey crawls under a blanket to sit with him and calm him. That link is so good that she and the dog become wonders at finding bombs and guns. They save thousands of soldiers' lives in 100 missions until both of them are injured by an IED.
The story does not end there. It continues through Leavey's determination to adopt Rex.
Kate Mara, from TV's House of Cards, disports herself well as Corporal Leavey, never giving in to sentimentality, a move supported by the sensible script by Pamela Gray, Annie Mumolo, and Tim Lovestedt. The fine supporting cast includes Edie Falco as Leavey's no-account mother, Bradley Whitford as her supportive father, and Common, amazingly good as her sergeant.
Gabriela Cowperthwaite, who produced the documentary Blackfish, balanced the violence with the depressions of war with cameras at dog and gun levels. She directed a heartfelt memorial to women and dog soldiers.