A relentless documentary filmmaker struggles to unravel the mystery of his uncle's death as an unknown adversary threatens to destroy the project and his family.

Madge Clayton, a society girl, mysteriously disappears. The police suspect a master criminal is behind the girl's abduction, but her brother, Bob, and fiancé, Bert Moore, help with the search. They unearth a scheme to kidnap another girl, Natalie Van Cleef, and the evidence takes Bob and Bert to an estate on Long Island.