The series tells the story of Franco Montero who works in the police force. After the death of his father he finds out he has a half sibling, Lorenzo. The boy is only eleven years old and has no other alive relatives, so a judge determines he must live with Franco. But Lorenzo is a very particular boy: he has a very high IQ rate, so in a way, he is like a little Sherlock Holmes and will help Franco solve very complicated murder cases.