Marco Buratti is a former Blues singer. Unjustly sentenced to seven years in prison, as former prisoner he remained obsessed with justice. He started to use his «skills» and his knowledge in the underworld and he becomes a very particular investigator: he feels more comfortable in the marginal and extra-legal world than among policemen and magistrates. He recurs willingly to the help of strange characters: he doesn't get his hands dirty, but he doesn't mind asking for "unconventional" help.