At the same time Marisa Hagan (Jacinda Barrett) discovers that her child (Tom Russell) is seriously ill, she also finds out that her husband (Richard Roxburgh) has been unfaithful for years. In desperation Marisa goes on a bizarre search in an attempt to turn her husband's serial affairs into a positive; an illegitimate child could be the vital donor that saves her son's life. A chance encounter with another parent, Connor (James Nesbitt) and his son Finn (Kodi Smit-McPhee), leads them on a journey of love and hope.