Many in these fact-lite days will know nothing of Giordano Bruno. Some will remember a statue in the Campo de’ Fiori in Rome; they may have a vague idea of a freethinker born out of due season, a kind of Don Cupitt or Richard Holloway of the Italian Renaissance, and a victim of the fire of the Inquisition. We may be tempted to consign him to history; to Alessandro Gallenzi, however, Bruno remains a fascinating historical figure, and he has done much assiduous and scholarly research to produce this decent and unpretentious thriller.The eponymous tower is in the Jordanian desert, just outside Amman. An American corporation – a kind of combination of the NSA, Google and the Library of Congress – has made its headquarters there: its goal, to digitise everything, for posterit