Weed smoking, foulmouthed Rocco Schiavone is an offbeat Deputy Commissioner of the State Police. For disciplinary reasons he is transferred to the Alpine town of Aosta, far from his beloved Rome. The sophisticated but cranky Roman despises the mountains, the cold, and the provincial locals as much as he disdains his superiors and their petty rules. But he loves solving crimes.

Achille, nine years old, intelligent, sympathetic, and stutterer. The parents decide to treat him and entrust him to Dr. Aglieri, who begins the therapy. Meanwhile the child knows other patients