What would you do if your adult children developed an age-defying disease that made them regress to childhood? How would you cope with seeing them go from man to boy and looking after them 24 hours a day? This new documentary tells the harrowing story of Tony and Christine Clark and their two sons Matthew, who's 39, and Michael, who's 42. Until their late thirties, they were totally unaware their brains were carrying a deadly neurological time bomb.