In the autumn of 1967, telephonist Prairie Humble and her Morris Minor 'Baby Blue' roll into Wheatsheaf, a town dominated by grain silos and a salt pan. Taking up a position at the local exchange, Prairie quickly becomes favoured by the townsfolk - especially Constable Timms and handsome geologist, Gil Sanders. But she soon discovers her colleagues have a penchant for eavesdropping, and when one of them disappears, Prairie wonders - can loose lips really sink ships?