Blair, Jo, Tootie, Beverly Ann, and Andy accompany Natalie to Australia, who is going to make a speech in the Australian counterpart of their school. Blair and Jo meet a guy who claims to be a policeman and entrusts them with something that he says is evidence against a criminal whom he says is approaching them. Later that guy breaks into their room and they knock him and they discover that he is a policeman and he tells them that the man they were talking to is a jewel thief who stole an opal but did not have it with him when they searched him. So he suspects that he gave it to them. While they are skeptical as to who is telling the truth, they play along until they can find out who is telling the truth. And besides they don't have it, it's in Natalie's backpack, who went out into the bush and is lost but a guy finds her and takes care of her.