Needless to say, Todd's journey, reconstructed here through letters and family history, was arduous; more surprisingly, so is Thomson's. As she and her husband cope with breakdowns, illness and the poverty of isolated communities, it becomes clear that parts of the outback haven't changed much since Todd first saw them.

In Charles Todd and his wife Alice, Thomson has chosen intriguing subjects. Charles is brilliant and ambitious but increasingly unaware of the needs of those around him, particularly his large family. Thomson isn't afraid to cast a critical eye: "Certainty had helped Todd to span a continent. It may not always have made him an easy companion." But the strongest presence in the book is the enigmatic Alice, the sparky young woman who made family history by proposing marriage to Charles. Frequently separated from Todd, Alice oscillates between bouts of sociability, fierce spirituality and depression. Was she happy with Charles? The Singing Line is an exploration of personal as well as technological connections and it seeks to answer that question. --Tamsin Todd