WriterPaul Matthew Thompson
DirectorIan Barber
Research stateCase file + location evidence
Spoiler-light premise
International thief Hercule Flambeau warns Father Brown that he intends to steal the priceless Blue Cross relic.
What to watch for
John Light’s first appearance as Flambeau and the beginning of the series’ longest-running intellectual rivalry.
Continuity tags
Conservative catalogue links for recurring stories—not a complete cast list.
Location evidence
This case carries explicit location links in the research catalogue.
- National Waterways Museum
Episode order and contributor credits: source record ↗