Moving stealthily in the background, always keeping their tracks well covered, the perpetrators of the terrible Black Secret conducted heir campaign with Michiavellian ingenuity.
Adventures of an American Secret Service-girl in search of an important German secret during the war. Chapters: [1] “The Great Secret,”; [2] “Marked for Death,”; [3] “The Gas Chamber,”; [4] “Below the Waterline,”; [5] “The Acid Bath,”; [6] “The Unknown,”; [7] “The Betrayal,”; [8] “A Crippled Hand,”; [9] “Woes of Deceit,”; [10] “The Inn of Dread,”; [11] “The Death Studio,”; [12] “The Chance Trail,"; [13] “Wings of Mystery,”; [14] “The Hidden Way,”; [15] “The Secret Host"
Bertram Millhauser
Screenplay
George B. Seitz
Director
Pearl White
Evelyn Ereth
Walter McGrail
Ray McKay
George B. Seitz
German spy
Harry Semels
Wallace McCutcheon Jr.
Frederick
Henry G. Sell
Marjorie Milton
Francis Wightwick
