That The Girl in the Case is not to be taken seriously is demonstrated in the scene wherein its dignified leading man Edmund Lowe dons a gaudy zoot suit. Lowe is cast as lawyer William Warner, who also happens to be an expert lock-picker. Both his legal and illegal talents are pressed into service when Tommy Rockwood (Robert Scott) hires Warner to open an old chest. This particular prop turns out to be a veritable Pandora's Box, unleashing an onslaught of intrigue, espionage, and murder. Janis Carter costars as Warner's Nora Charles-like wife, whose inability to mind her own business nearly results in her demise.