As if deeply disappointed that America didn't right itself after seeing its doom in the comic forecasts of Love in the Ruins, Percy/Jeremiah returns with less funnystuff, fewer pages, zero fantasy, and much more resolve--none of which keeps Lancelot from being precious goods. "I will not tolerate this age," insists Lancelot Lamar, nuthoused after incinerating his Louisiana homestead while his unfaithful wife and her movie-star buddies slept within. A visitor has arrived--a priest, a psychiatrist, an old friend--and Lancelot explains himself in alternate bursts of confession and sermonizing. Pieces of the true-crime, true-love story pull irresistibly taut: discovering wife Margot's past adultery (a daughter's impossible blood type), logging her current dalliances (cameras rolling in every bedroom), shooing away the innocents and gathering the sinners together before pumping in the methane. If the preoccupation with fidelity seems dated Lancelot's lamentations over "the great whorehouse and fagdom of America" let us know that the anachronism is intended. With a vengeance. This "Knight of the Unholy Grail" seeks one real sin in a Manson world where murderers are sick, not bad, where women have stumbled on the crude reality of sex ("ah, sweet mystery of life indeed"), where Lancelot's teen-aged daughter triples up with bisexual film folk. Solution? "The future must be absolutely new"; Lancelot plans a log-cabin existence with the mute gang-rape victim in the next cell. Does this particular last gentleman speak for Percy? Probably not, since the priest who listens throughout is called Percival and is about to talk for the first time as the novel ends. But Lancelot's tirades will have readers pausing for breath and for thought, caught by surprise and kept from sleep by a great novelist working in the public interest. "Which is worse, to die with T. J. Jackson at Chancellorsville or live with Johnny Carson in Burbank?" You decide.