Molly Gumnut loves her neighbour's cat, but when she catches him attacking a baby bandicoot, she runs screaming into Mrs Wilson's garden. After shooing the cat away, Molly rescues the injured critter and names him Furble. But when she takes him to the vet, he says she can't keep him because bandicoots are protected native animals and must to go to a wildlife sanctuary.
Molly doesn't let that stop her from keeping Furble. She informs the vet that her grandmother is a volunteer with a wildlife rescue and would gladly look after him. The vet gives in, but Molly is horrified when Grandma insists Furble will be released back to his own territory when his wounds have healed. Molly can't let that happen, 'cause that's where the big mean cat lives.
Well, no way will she let Tiddles hurt Furble again. She doesn't care if she gets into trouble for yelling at the neighbour, or disobeying her parents. She kidnaps the little bandicoot and takes him on a journey to find him a safer home. When things go badly wrong, Molly realises she's made a bad mistake. Now Furble's in more danger and so is Molly.