Last year, Cliff Jardine and Sue Ward discovered that they are half-brother and sister after both applying separately to the show. Previously unaware of each other's existence, they were overjoyed to find a sibling. Since meeting, Cliff and Sue have formed a powerful bond, but they have been rocked to learn that their birth mother has chosen not to have contact with them. After being reunited themselves, Ron Williams and sister Christine are now determined to investigate a family rumour that they may have two more half-siblings. Their mission to solve this mystery launches an incredible new search - one which takes Ron and Christine to the other side of the world.