Janey Brown thought she was an only child. Now 'Joanie' has turned up claiming to be Janey's secret twin! But when Jane Blonde is posted to Australia to investigate a suspicious sheep farm, it becomes clear that Joanie isn't quite what she seems. Has Janey exposed an undercover cloning operation? Soon Janey's dodging more than boomerangs: there are multispies on the loose including Jane Blonde's own evil twin!