The past can be as tempting a subject of contemplation as a better future, but while we can shape the last according to our dreams and plans, the first is impossible to change. What happened, happened. Despite all, the question “what if things had been differently” sometimes springs to our minds with such force that we get absorbed in futile reflections. Of course, such ruminations use to focus on a rather recent past and on something that we did or didn’t do in a specific situation. Science fiction writers, however, usually step further back in History to fill entire novels with alternative pasts. Out of a sudden whim the protagonist of my bookish déjà-vu, The History of the Siege of Lisbon by José Saramago, alters a minor detail in the proofs of a history book that he corrects and thus begins his alternative account of events and a love story…