Australia's isolation from other continents for tens of millions of years produced an animal world that breaks the rules seen everywhere else, and this film tours it species by species. Marsupials dominate the frame: kangaroos and wallabies on open grassland, koalas and native cats in the forest canopy, wombats underground, most of them filmed at night when they are actually active. The film compares these pouched mammals against eutherians, the placental majority elsewhere, using forests in South Africa as the counterpoint and weighing how gestation length and cranial development in the newborn differ between the two groups. From there it moves to the animals that defy both categories: birds standing two meters tall whose males do the incubating, a fish with lungs, blue-tongued lizards, and the monotremes, platypus and echidna, mammals that lay eggs instead of giving birth. The throughline is a continent that kept running a separate evolutionary experiment long after the rest of the world's mammals had settled on live birth.