A gemstone named the Mermaid's Scale appears in a secret, underground auction, and Lupin is coerced by the queen of the underworld into stealing the rock for her. Lupin however quickly discovers not only that the stone is a forgery, but that the real Mermaid's Scale is part of an unsolved riddle involving the mysterious girl Misa that leads to transcending mortality.

Three black revolutionaries gun down two New York City police officers. The subsequent investigation puts a white assistant DA and a black police detective on the trail of the killers that leads from New York to San Francisco and down to New Orleans.