In a forgotten corner of Puglia, Gianni wanders alone every day, searching for meaning in the grief that haunts him after the death of his wife Ada. His only daily act is to post letters in an old, rusty mailbox. Letters for her, which no one reads. Or maybe they do. One day, an unexpected response: a blue letter, signed by a stranger. An attack. A judgment. A condemnation. But also a signal: there is someone else trying to survive the pain, with anger or silence. And he is not the only one.