Frankie, a talented illustrator who lives with her partner Craig and his young son Fergus, sets off to Yorkshire determined to trace her father, Harry Mortimer. But when she arrives, she is horrified to find Harry and his wife Jean are celebrating their golden wedding anniversary with their children, family and friends. Frankie's unexpected arrival throws the close-knit family into disarray and causes a devastated Jeanie to disappear, leaving the rest of the Mortimers to cope without her. As Harry's wife and children struggle to come to terms with this shock revelation, Frankies own happiness is threatened. She and Craig must decide how to face their new, uncertain future together.