What happens when the facts of history are replaced by the mysteries of love?

When Raimundo Silva, a lowly proofreader for a Lisbon publishing house, inserts a negative into a sentence of a historical text, he alters the whole course of the 1147 Siege of Lisbon. Fearing censure he is met instead with admiration: Dr Maria Sara, his voluptuous new editor, encourages him to pen his own alternative history. As his retelling draws on all his imaginative powers, Silva finds - to his nervous delight - that if the facts of the past can be rewritten as a romance then so can the details of his own dusty bachelor present.