My Lady Incog. (1916)

"In a Rare Combination of Laughs and Thrills Miss Dawn as a Girl Detective Faces Extreme Perils Unflinchingly"

Financial troubles force Nell Carroll, a thoroughbred, to seek employment in a detective agency which has just taken up the trail of a very baffling jewelry robbery in an exclusive summer colony. In order to work from the inside, she is sent to the place as the Baroness Du Vassey.