The Ghost, a legendary figure who has gone by so many aliases his real identity is a mystery, has created a double-edged hallucinogen that is both a blessing to psychiatry and a powerful weapon that can ignite mass hysteria. When the mad scientist is double-crossed by one of his own minions, Agent Sydney Bristow must accompany him to his undercover clinic in Switzerland and help him learn which of his proteges stole the drug and sold it to a chemical weapons dealer.

However, this plan doesn't sit well with Jack Bristow, who shares a past with the Ghost....In fact, he thought he killed the man in a Vietnamese jungle years ago. Now Jack must determine if his mind is playing tricks on him, or if their wartime encounter was just another one of the Ghost's twisted psychological experiments....