Marco Merani, wizard of marine engines, has a wife and daughter he loves and a job he adores. When one of his best customers is murdered, he discovers that the rafts he made for him were used to transport drugs. A few days later two men show up at his construction site asking him to continue with that job.

Marco, thanks to the trust that Aurelio shows him, accepts the invitation of his policeman friend and becomes the first civilian infiltrator in history. The thousand lies and the many displacements he is forced to do create a growing tension with his wife, his father and his family. Furthermore, Aurelio's attitude, who treats him almost like a brother, makes Inspector Vexina suspicious.

Marco, forced by Aurelio to leave for South America, meets the boss's family and his fellow traffickers. The man would like to end that story, but Mario convinces him to accept one last job: preparing a boat for a special delivery. Aurelio, at the last moment, asks that Marco be the one to drive the boat. Marco hesitates but the Italian police guarantee him protection.