Christmas morning, 1963: fifteen-year-old Kitty Doherty gives birth in a hostile Irish convent. Kitty knows her baby presents a huge danger to her family's Catholic community back in Liverpool's Four Streets. When her baby is adopted by a wealthy family, Kitty considers the problem solved. But soon it's obvious the baby is very sick and only his birth mother can save him. In Liverpool, things have begun to settle down. The Doherty’s are coping with the tragic consequences of Kitty's pregnancy. But now all that is about to be put at risk once again.