US Marine Captain Sam Cahill is well respected, not only by his colleagues but also by his family, especially his ex-Marine father, Hank Cahill. Although he is also loved by his family - his high school sweetheart wife Grace, and their two young daughters, Isabelle and Maggie - they, Isabelle in particular, do not like his frequent absences. Coinciding with the imminent and only latest of his deployments to Afghanistan is the release from prison of his brother, Tommy Cahill. Grace does not much like Tommy, and Hank feels Tommy has not earned his respect, which does not change by Tommy's actions post-prison. Shortly into this tour of duty, the Cahills learn that Sam has been killed in action. Largely because of Grace's grief, Tommy finally comes to the realization that he needs to become a responsible adult, filling the role vacated by Sam in more ways than one. In their mutual grief, Tommy and Grace fall into each others arms - which does not go any farther than a single kiss - and the girls see in their Uncle Tommy the father that they don't have in Sam, namely one who is constantly present in their lives. This new life changes when they all learn that Sam was not killed, but was taken captive in Afghanistan and now rescued. Sam's return leads to a difficult transition for all concerned, not only because of Grace and the family having settled into a life without him and with Tommy, but also because of the trauma experienced by Sam in Afghanistan in relation to how he sees Grace and Tommy together.