question: What is the first book in a duology of books from the late 90s by the author who wrote Heir to the Empire?
answerText: Specter of the Past
questionEntity.name: Q66724896
questionEntity.entityType: entity
questionEntity.label: Heir to the Empire
questionEntity.mention: Heir to the Empire
questionEntity.name: 1
questionEntity.entityType: ordinal
questionEntity.mention: first
questionEntity.name: 1990:1999
questionEntity.entityType: date
questionEntity.mention: 90s
answerEntity.name: Q742167
answerEntity.label: Specter of the Past