Pat and Ruth Beckett have retired from Sydney to the sublime landscape of the far south coast. To their garden, to their books, to their island in the lake.   They want no part of the madness of Harbourside Grammar, monstrous celebrity billionaire Buckets Barrington, or the sinister Magnareach Corporation.   But the madness wants a part of them.   Can great books, small black ducks, perfectly formed compost and proper placement of the apostrophe be enough to defend their paradise?