Turn of the Cards — George R.R. Martin

The Rox is history and Mark Meadows is on the run, pursued by the CIA, the DEA, and the Wild Card mistress of the winds, Mistral. But the renegade biochemist has his own secret weapon: three personalities buried in his psyche, each possessing Ace powers, each activated by mind-bending drugs.

Fleeing, across Europe and Asia, Mark meets a crazed Vietnam veteran with an astounding plan--to lead an army of Jokers in a war of conquest. Caught between Jokers who despise him and vats who want him dead, Mark must decide whether to unleash his Ace powers for a madman's bloody dream, or to stay true to his peaceful ideals--and die.