Lady in the Lake by Laura Lippman
Turns out that even if still waters run deep, there's no current, they can't take you anywhere. All they do, eventually is close over your head. "Would you tell me one thing about her, anything? A detail I can't know from reading things."... Another long silence, until she despaired that he would ever speak. But then: "She was like a poem." "What?" She hadn't expected any response, much less an answer that was at once tender and provacative. "There was a poem they made us memorize when I was in school. I never understood it. But it was about a woman, whose looks went everywhere." "'My Last Duchess.'" "That sounds right." "'She looked on, and her looks went everywhere.'"