Journalist Sheehan wrote eloquent nonfiction about Central American upheaval (Agony in the Garden, 1989); here, however, his North American protagonist clumsily penetrates Mexico's heart of darkness in a heavily strained and racially regressive allegory. Tall, blond artist Adrian Northwood--favored over his short, dark reprobate brother--inherits his dark ungainly father's ill- gotten fortune. His high-minded blond mother lives in splendor but refuses to touch the filthy lucre (except to contribute millions to the Vatican). Adrian, meanwhile, suffers from a lack of talent and a constant longing for 18th-century order and beauty. Reeling from the accidental deaths of his dark, disrespectful, Egyptian-born wife and angelically blond son, he builds a sanctuary for Central Americans in Texas, reaches out to glue-sniffing children and to a fatalistic whore whose unseen brother steals Adrian's paintings, including his blond, blue-eyed Saint Francis. Adrian crosses the border in pursuit, intermittently divests himself of privilege, withstands savage torture in a Mexican prison by composing his alumni notes and reviewing the glories of Western civilization. Humble prisoners embrace his ``radiance''; the stealer of the paintings proves to be Adrian's dark opposite--a talented, instinctive artist lacking in technical skill. A dark but noble baby and some white skinhead villains do little to temper the relentless blond/dark civilized/savage polarities here. There's attempted humor (border town ``Downsville''; ``Motel 5´''), and Adrian's fascination with lost dark souls makes him silly at times, but--as God's fool--his saintliness is never in doubt: the novel acknowledges the interrelationship and attraction between North and South, but any saving irony is lost beneath the author's heavy hand.