Like several previous books about Vicky Austin, Troubling a Star is told in the first person, with Vicky as the narrator. It begins with Vicky stranded alone on an iceberg off the coast of Antarctica. The novel proceeds to tell in flashback how Adam's Great Aunt Serena paid for Vicky to visit Adam at Eddington Point in Antarctica, and of the interesting people and unexpected dangers she meets along the way. Despite Vicky's concerns about an apparent cooling in Adam's affection for her, it is established that their relationship is a strong one.
Part of the story takes place in Vespugia, the fictional country first mentioned in A Swiftly Tilting Planet. The events of that book have a strong bearing on the dangers Vicky faces approximately thirteen years later.