Spies from Japan conspire to steal the Channing "preparedness" fortune and invade the United States, beginning in New York, then allying themselves with Mexicans across the border. They are stopped by the efforts of munitions factory heiress Patria Channing and U.S. Secret Service agent Donald Parr.

The heroine had little time for romancing newspaper reporter Walter Jameson, what with Doctor X, alias Marcus Del Mar, threatening American democracy in general and master detective Craig Kennedy's designs for a new torpedo in particular. Whenever Doctor X has Elaine or Jameson in his grasp, they are inevitably saved in the nick of time by a mystery figure garbed in black.

One of many Pearl White silent action movie serials. CHAPTER TITLES: 1. The Serpent Sign; 2. The Cryptic Ring; 3. The Watching Eye; 4. The Vengeance Of Wu Fang; 5. The Saving Circles; 6. Spontaneous Combustion; 7. The Ear in the Wall; 8. The Opium Smugglers; 9. The Tell-Tale Heart; 10. Shadows Of War.

Elaine Dodge is the beautiful young daughter of Taylor Dodge, president of the Consolidated Insurance Company. When Mr Dodge is murdered by a mysterious cloaked figure known only as the Clutching Hand, Elaine enlists the aid of Craig Kennedy to unmask the killer