Secret Agent X-9 (1937 serial)
G-Men learn that "Brenda", notorious jewel thief, is heading for the US, to steal the Belgravian crown jewels currently on exhibit. The jewels are placed on a ship bound for Belgravia. However, the guard is murdered and the treasures are stolen. Agent Dexter, alias Agent X-9, trails Blackstone, one of the gang members, who hides the jewels in a safe deposit vault of a bank. He takes the bank receipt to an art shop, where Marker, a paid accomplice, conceals it between an oil painting and its frame. Dexter arrests Blackstone and pursues Marker with the full intention of unmasking of the mysterious "Brenda"...
Chapters
1. Modern Pirates
2. The Ray That Blinds
3. The Man of Many Faces
4. The Listening Shadow
5. False Fires
6. The Dragnet
7. Sealed Lips
8. Exhibit A
9. The Masquerader
10. The Forced Lie
11. The Enemy Camp
12. Crime Does Not Pay
235 minutes 12 Chapters 1937