Blake of Scotland Yard (1927)

12 part silent serial- 1. The Castle of Fear 2. The Spider's Web 3. The Vanishing Heiress 4. The Room Without a Door 5. Shots in the Dark 6. Ambushed 7. The Secret of the Coin 8. Into the Web 9. The Baited Trap 10. The Lady in White 11. The Closing Web 12. The Final Reckoning. A prequel to The Ace of Scotland Yard.