In 1917, Gino Montanari, an elementary school teacher from Romagna, was forced by the principal of his school to volunteer for the First World War because of his libertine and anti-interventionist behavior. With the threat of being expelled from all schools if he refused, Gino was reluctantly sent to the front in a small outpost in Valtellina, where as a heliographer he had to transmit Morse signals with sunlight. His life would be profoundly changed by his encounter with a young illiterate man, with the enemy, and with a series of individuals from various parts of Italy.

When a man disappears and leaves a daughter and mother in heavy debt they have to live on a houseboat to make ends meet.