A female private detective, Harriet Zapper, is hired by a rich old man to find his missing children, and becomes involved in counterfeiting and murderA female private detective, Harriet Zapper, is hired by a rich old man to find his missing children, and becomes involved in counterfeiting and murderA female private detective, Harriet Zapper, is hired by a rich old man to find his missing children, and becomes involved in counterfeiting and murder