Father Brown starts solving crimes, much to the annoyance of his housekeeper, the police and especially his bishop, who is not amused by a priest playing detective.
Father Brown is only too happy to interfere with the work of the police in solving tricky criminal cases, usually with resounding success. That's why the clergyman is transferred to a sleepy island called Abbott's Rock. At first, nothing happens there, but somehow Father Brown seems to be attracted to crime: Soon a gang of thieves is up to no good on the island. So Brown makes the headlines again, and is punitively transferred once more. This time he finds himself in a quiet Irish millionaire community.
Small time crook Napoleone falls into an unlikely gang made up of a gangster, called The Baron, and his two cohorts, Agonia and The Captain, where Napoleone takes them to Rome where they shack up with a shady used car dealer caled Il Cajella to help finance their new life of crime by planing to rob a statue from the Vatican. But a big-time American gangster, named Joe Ventura, hears about the heist and wants the priceless statue for himself by having his mistress, Samantha, come onto and betray the woman-hungry Cajella to give the statue away to her.
