Rosso writer in lack of inspiration is invited to a book signing in a small village but it is the fiasco. As usual he drinks too much and ends the night by destroying the moped of the one they call the Indian. Forced to apologize, he is surprised by a group of children, and together they discover the Indian's corpse. The children know more than they let on, and manage to convince him to help them investigate the murder of their friend. He is then confronted with the world of children, a world made of stories, where reality is told and things only exist because they are believed. Little by little he enjoys himself and finds his inspiration, but a detail escapes him, the desire of revenge of the children. Rosso is suspected by the people of the village and the investigation turns into an expedition to prove his innocence. But the group is trapped by the real murderers, Jean and Saskia, the Indian's own sister. She wants to recover his inheritance, a treasure that the Indian has secretly entrusted to the children. Rosso is sequestered and reveals the position of the fort. While he manages to escape, the children kill Jean who is in pursuit. They all end up in the fort and war breaks out. Despite their tenacity, they are no match for Saskia's rifle, and Rosso sacrifices himself to allow them to escape. He and Saskia kill each other. Before he dies, he bequeaths his book to them, but it is up to them to write the ending.