Penn Gwinn and his agency partner, Jim Starret, remained in Thailand after their involvement with the Defense Intelligence Agency during the Viet Nam 'non-war', and opened a saloon for their subsistence. They expected to retire, but the warlord of the Shan State in the Golden Triangle area of Asia, who is known as the Prince of Darkness. They are forced to get involved fighting against opium smuggling and the rivalry between the D.I.A. and the C.I.A. in another one of their inter-agency battles. This exciting and interesting story reveals just some of the problems involved in fighting the drug wars in Asia.