When Regan fails to become the first woman to become a navy seal, she is left adrift. She was so focused on her goal, she had no other life to fall back on. Until she gets word her brother has died in a horrible car accident. Her family needs her, so she goes home. Grief gives her a new focus. Further bad news gives her a target. Hurt her family and she won't just hurt you back. She will bring you down.
When a female lead character is a tough, strong woman on a mission, you have my attention. When the rest of the story is just as good, you have a fan. Regan has a lot to deal with and she handles herself very well. She never turns into a cartoon character with superpowers. She remains a woman with everyday problems that is willing to take on the world when her family is harmed. I think this would make a great movie franchise. An action heroine with a family, ups and downs and problems just like the rest of us.