In Yugoslavia, Solo and Illya are aided by Marion Raven (Jill Ireland) in stopping Gervaise Ravel (Anne Francis) and her partners from using a fear gas to overthrow various governments. While two of them are captured, two of them escape, and the story continues in "The Giuoco Piano Affair"

The conuation of "The Quadripartite Affair". Gervaise Ravel (Anne Francis) returns and Solo and Illya again enlist Marion Raven (Jill Ireland) to help them pursue her through the Andes, where the treachery of police lieutenant Manuera (James Frawley) impedes their efforts to capture Ravel.

Solo and Illya go to India to help Suzanne de Serre, a French botanist trying to find out why the jungle is dying and local natives are disappearing. Prince Panat and Drusilla Davina, along with Colonel Quillon, are systematically using a chemical to destroy the jungle and kidnapping natives to work in the jewel mines for the prince.