Three trials that changed the history of Australia, brought to life by transcripts and actors in stick-on mutton-chop sideburns. A worthy idea, but is historian Michael Cathcart over-egging the pudding when he declares of this week's grim subject matter - the massacre of 28 Aborigines at Myall Creek in New South Wales - that ''at stake was the legitimacy of white settlement''? Without getting all Geoffrey Blainey about it, the notion that whites in 1839 were second-guessing their right to colonial land seems fanciful. It smacks of 21st-century racial politics rather than any 19th-century notion of property rights. It's easier to agree with the re-creation's earlier proposition that the trial of seven white men for the murders was really about whether Aborigines had a right to be protected by the law or whether they were aliens in their own land. As a drama, this Ana Kokkinos-directed episode hangs together fairly well, with evil squatters and unfortunate witnesses victimised over their willingness to stand up for a moral right.