Will has been happily married to Harmony for eighteen years, but she is recovering from the loss of a baby she didn't know she wanted. Although she willingly accepted her husband's desire not to have children when she agreed to marry him, the accidental pregnancy awoke strong maternal feelings within her and six months after the miscarriage she is desperate to try for another baby. When she raises the subject with Will at her best friend's birthday party, he is horrified at the suggestion. Harmony removes herself from the crowd and meets with a handsome and enigmatic stranger who boldly suggests that they leave the party and have dinner. Harmony declines. Soon after, Harmony discovers that the stranger's name is Luke and that he was at school with Will: they were blood-brothers. Will's inability to discuss his past - his destructive relationship with his deceased father and a miserable school life infected with a culture of bullying - is no longer possible and he is forced to confront some difficult memories and also the guilt he's carried with him since his schooldays.
The situation is complicated by a fierce attraction Harmony has for Luke and, angry at Will for confessing a secret too painful for her to cope with, she embarks on an intense affair. With Will trying everything he can to salvage their marriage and rebuild her trust, Harmony ends her entanglement with Luke but he has no intention of giving her up. Harmony finds herself caught in a dangerous love-triangle with the husband she loves and the obsessive stranger who blames him for everything that's gone wrong in his life.