Big Zapper Collection

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

When Harriet Zapper is hired to find the identity of Karel Duval, and the true heir to the Duval family fortune, a bloody trail of murders leads the Big Zapper from London to the South of France and into a hornet's nest of betrayal and death.