Diego is a law student who lives with his mother and sister in a historical Torino quarter. One day, coming back home, he finds his mother dead, murdered. This is only the beginning of his hell. All evidence is against him: he is charged and shut in Cuneo prison, called “Il Grigio” by all prisoners In that jungle, only one thing keeps him alive: the will to prove his innocence and to find his mother’s killer. But in that place, the priority is another one: surviving. The prison is divided into gangs: the most powerful are Calabrians and Sicilians, then Slavs, Moors and minor groups. After them come stray dogs like Diego, those who do not belong to a group, are most in danger. Diego finds out that the man who murdered his mother might hide in that circle of hell. What Diego doesn’t know yet is that he is not there by chance. In 41 Bis there is the man who framed him and wanted him by his side: his father. A Cosa Nostra boss who remained heirless and decided to summon his only illegitimate son to make him his successor. The man can prove his innocence. If Diego accepts his fate, he will also get his freedom.