Life seems idyllic for Marisa and her son, Jack, until a poor performance at a school soccer match ends with Jack in hospital and Marisa trying to find her husband, David, who is interstate at a conference.  In fact, David is planning to leave Marisa for his current mistress, with his phone off and not a care in the world.
Jack is diagnosed with leukaemia and the only possibility of a cure is if David has had a child from one of his many flings who could be a bone marrow donor.  So Marisa looks back through his diaries, figures when he could have been having affairs, and goes out door knocking.  Unsuspecting women face a desperate mother as Marisa searches high and low for possibilities and the full scale of David’s infidelity is revealed.
Meanwhile, Jack befriends Finn a young Irish boy in the next bed.  He has been travelling the world with his father, Connor.  Initial disdain turns to mutual respect as both Marisa and Connor find their own ways to deal with their respective sons’ illnesses.