Taylor Valentine, Eva O'Sullivan, and Joe Roberts are siblings by choice. They believe in The Kindred Code: blood means nothing and love is everything. As their lives follow different paths after college, they wonder if their mantra will stay true.

When word gets out that Professor Stuart Morgan had dated Taylor while in his class, the publicity takes a toll on their relationship. Under the stress, Stuart struggles with his PTSD. With his son at a sleepover, Officer Matt Connor invites Eva to his home. Over the weekend, volatile confrontations erupt between Matt's mother and Eva. The rural town enjoys the uproar.

FBI Division Director Peter Bingaman asks for Joe's help on an unofficial case. Before heading to Quantico, Joe jumps at the chance to test his skills. They quickly uncover horrendous crimes. Suddenly, Joe's in over his head. Will Joe's family put aside their problems and come to his aid before it's too late?