The twins are finally found and reunited with their family.
Uncle Bill takes everyone on vacation to Spain. As they start the great vacation, Mr French and the twins get separated. Bill and Cissy join Mr. French in the search for Buffy and Jody.
Bill, Cissy and Mr. French continue to search for Buffy and Jody in Spain. Meanwhile, the twins are being cared for at a school house run by nuns.
The partners and a flighty but talented agent (Arlene Golonka) seek to retrieve Soviet documents in Acapulco.