Since the programme began in 2011, Long Lost Family has reunited more than 100 people with relatives. In this series, Davina McCall and Nicky Campbell revisit nine of the most extraordinary searches. In the first edition, they catch up with twins Jennifer and Kathleen, who unknowingly lived just three miles from each other in Rotherham before their reunion, and Polly and Steve, a mother and son who had been apart for more than 50 years. Plus, Laura and her half-sister Alison, who were brought together after Laura's mother died.

Sarah Gale enjoyed a happy childhood with two loving adoptive parents, but she'd been desperate to track down her birth mother and been trying to do so for 20 years. The programme found Susan who, after having Sarah, had moved to South Africa in the 1970s and went on to have a son. Three years after being reunited, Davina and Nicky hear how mother and daughter have grown close, and Susan prepares to meet Sarah's adoptive mother Rosemary for the first time. Plus an update on Jeannie Elgar, who met her brother's adoptive sibling Robert, and Stella, who was reunited with daughter Maxine after she made the decision to have her adopted at 18 months old.

This final programme revisits three stories of women reunited with their siblings. Cherry Durbin who was searching for one sister, unexpectedly reunited with two. The three sisters all grew up as only children, so how have they adapted to their new roles as sisters? Maureen Saville was reunited with a brother and sister. Have her siblings been able help her understand why her mother abandoned her as a toddler? Fiona Dunn and her sister Maureen were reunited two years ago and now Fiona has finally met her birth mother Pat whom she had believed was dead.