Étienne has just been dumped by his girlfriend Mathilde. Heartbroken and stuck with non-refundable plane tickets, he decides to visit Rome alone. There, he wanders the streets, belting out love songs. He knows an endless number of them, and often borrows lyrics to express himself. His wanderings eventually lead him to a magician’s shop. But instead of curing his heartache, the potion he drinks sends him back to ancient Rome, where he must fight before the Empress, who is none other than his ex!