Suspense novelist Ethan Black has made a regular business of getting inside the heads of his heroes and villains in order to make clear that they are neither wholly good nor wholly bad, neither all strength nor all weakness. His taste for psychological nuance has inspired critical plaudits, and was keenly on view in 2003"s Dead for Life, which featured an ostensibly textbook-caliber sociopath who is eventually shown to be no less complex or deserving of sympathy than anyone else, including Black"s protagonist, multimillionaire New York police detective Conrad Voort. Sadly, At Hell"s Gate, the fifth entry in the Voort series, pales by comparison with that previous work. In his effort to explore the depths of Voort"s fears, Black has produced a tale that sacrifices emotional intrigue to vengeful violence. Things begin promisingly enough. Voort, the Jaguar-driving scion of one of New York"s founding families, is kayaking with his impossibly beautiful, on-and-off girlfriend, Camilla Ryan, in a treacherous stretch of the East River called Hell"s Gate, when they encounter the corpse of a murdered taxi driver. Turns out the cabby was fascinated with old shipwrecks, including a riches-laden 18th-century frigate that might be sunk near Hell"s Gate. But Voort"s homicide probe leads him well beyond treasure hunting, to arson and death aboard a tugboat--and eventually into the clutches of a remorseless mercenary named Leon Bok, who threatens the cop with sexual debasement and the slaying of his family, unless Voort leaves town for a couple of weeks. Traumatized, increasingly paranoid of further attack, and fearing that he"s "no good as a man anymore," Voort flees to Argentina with Camilla. But he soon returns and, under an alias, too boldly resumes his inquiry, which leads to revelations of international money laundering, divisiveness within Voort"s usually close-knit clan, and a climactic shootout that begs for cinematic adaptation. Black--the pseudonym used by a New York journalist--would have done better completing his portrait of a golden-boy treading the precipice of collapse, and left all the fireworks to lesser novelists. --J. Kingston Pierce