Nigel Morland's eccentric heroine of more than twenty novels is hired by Scotland Yard. Her first case is the investigation of a murder linked to a psychic society.
The role is essayed by Mary Clare, doyenne of the stage, who usually wound up playing villaineszes on the screen. She plays her as abrupt, self-assured, and bumptious. It's an attractive performance. I suspect her seconding to the Yard is part of the the British reticence to having murder mysteries solved by amateurs. In the US industry, anyone could solve a murder, and many a fast-talking reporter did so. In Britain, some connection with officialdom was de rigeur; even Lord Wimsey had a brother-in-law on the Force. Amateurs were often seen interfering with the smooth operations of the omniscient peelers.
Aside from Miss Clare, it's a rather dull affair. Originally it was planned as the first of a series. No further movies eventuated.