Father Brown tries to transport a historically important cross to Rome engaging in battles of wits and faith with a thief and pursuing policeman. The thief, named Flambeau (Finch), is a master of disguise and is elusive, as Father Brown pursues him and tries to convince him to abandon his criminal career.　　During the making of the film, Alec Guinness was mistaken by a small boy for an actual priest. This episode appears to have played a part in Guinness's later conversion to Roman Catholicism.

　　《穿墙人》（Le Passe-Muraille）改编自法国作家马歇尔‧埃梅的著名小说，音乐剧版本曾荣获法国最具权威的Mollier奖（最佳音乐剧奖，最佳导演奖）　　电影版由《虎口脱险》男二号布尔维尔主演：一个普通的公务员迪特律（音）有一天突然拥有了能穿墙的特异功能。该剧描述了利用穿墙的功能，洗劫宝石店，帮助邻居的迪特律爱上一位检察官的妻子伊莎贝尔发生的故事。