Duplicity tells the story of Carlos, a counterculture refugee from the 60's, with a special interest in unsolved mysteries of the past, who earns a meager living as a psychic detective in New York City in the 1990's. He sees the message, “Judge Crater, Please call your office,” scrawled on a message board at a party. Amused at first, later he remembers the story of Judge Crater. Curious about the case, he researches the Crater story and begins speculating about the possibility of reaching Crater’s spirit to learn the true story of his disappearance.
He begins by contacting three of his psychic associates—Joe Davidson, whose ESP provides a source for profitable "insider trading" in the stock market, Maria Polska, an ex-hippie in Hollywood gypsy garb who tells fortunes in Washington Square, and Borys, a refugee from World War II Europe. Each psychic offers Carlos information about the missing judge, and through one, Crater’s spirit is actually contacted.
Angry at being called to answer questions, Crater’s spirit issues a warning: Carlos will learn Crater’s fate, but will suffer for it. The mystery follows Carlos, revealing Crater’s past of violence, dual personality and psychic murder. Powerfully intermingling the lives and consciousness of two men—one dead and the other alive—Duplicity demonstrates the power of the dead over the living. For Carlos, Crater’s story becomes a journey into possession by an evil spirit through the merging of his personality with Crater’s and reliving the last days of the missing man’s life—revealing themes of disappearance, dualities of existence, and personal disintegration, ending with Crater’s death—and perhaps Carlos’ death as well.