Warner Oland proves there was life before "Chan" in this quite well paced drama about a scientist who is devastated by the death of his young daughter and fixated on revenge on the royal "Petroff" family whom he feels were responsible. The film is probably most remarkable because Oland's character is named "Boris Karlov", and there is some evidence that this character (though from an earlier iteration) was the inspiration for the stage name later taken by the must less enigmatically named William Henry Pratt! Back to this effort, and Oland works well as a baddie, helped by some decently atmospheric settings and lighting, and by a strong, amusing, performance from Clara Blandick as "Abbie". Technically, it's all a bit basic and the script could be doing with a bit of livening up, but it's still quite fun to watch and kills an hour easily enough.
