Los Angeles, fall 1988. For some time, a ""prognosticator"" named Sybil Divine has been exposing her apparent ability to predict earthquakes. She intends to extort money from L.A. Mayor Quail [sic] with her big scam. Everyone in town is convinced she can predict the big quake that will rock Southern California within the next half-century. Assistant Chief Rosa Morales knows better, as do Kate and George. They must prove it.

New York City, November 1988. Kate and George have just moved in to the Mathnet division at NYPD, with a new chief and a new ally, cabdriver Benny Pill. As they are fresh off ""The Case of the Ersatz Earthquake,"" Kate and George are well-prepared to hear about another prognosticator. This guy worked long hours to swindle five prominent city lawyers out of a few thousand bucks by predicting the results of a horse race.