The year is 1993. Cuba is at the height of the Special Period, a widespread economic crisis following the collapse of the Soviet bloc. For Julia, a mathematics lecturer who hates teaching, Havana is at Year Zero: the lowest possible point, going nowhere. Desperate to seize control of her life, Julia teams up with her colleague and former lover, Euclid, to seek out a document that proves the telephone was invented by Antonio Meucci in Havana, convinced it is the answer to secure their reputations and give Cuba a purpose once more. From this point zero, Julia sets out on an investigation to befriend two men who could help lead to the document's whereabouts, and must pick apart a tangled mystery of sex, family legacies and the intricacies of how people find ways to survive in a country at its lowest ebb.