'Alexandre Lourenço recounts his daring adventures with his older brother, the inventor Bartolomeu, aboard their wildly innovative airship, the Passarola, or "great bird." After finding rich patrons in Lisbon to fund Bartolomeu's flight obsession, they make their successful maiden voyage on the vacuum-pumped Passarola in 1731 in the presence of His Majesty João V. However, the brothers run afoul of Cardinal Conti's Inquisition and flee to France, where they are championed by the Enlightenment regime of Louis XV, as long as their airship can serve his purposes. Commissioned by the Académie des Sciences to measure distances to the polar circle, the brothers set out on a harrowing trek into the extreme northern regions, where Alex is beset by hallucinations of a splendid phantom city, and they must turn back. They cannot offer indisputable proof of what they saw during their exploration, so, disheartened they separate—Alex back to Brazil, to lead a mediocre existence, and Bartolomeu off to incredible adventures in India and beyond.'
Source: Publisher's Weekly.