WHEN JOHN DORTMUNDER, relieved, walked out of Pointers and back to the main sales floor of the O.J. Bar & Grill on Amsterdam Avenue a little after ten that Wednesday evening in November, the silence was unbelievable, particularly in contrast with the racket that had been going on when he'd left. But now, no. Not a word, not a peep, not a word. The regulars all hunched at the bar were clutching tight to their glasses as they practiced their thousand-yard stare, while the lady irregulars mostly seemed to be thinking about their canning. Even Andy Kelp, who had been sharing a bourbon with Dortmunder down at the far end of the bar while they waited for the rest of their group to arrive, now seemed to have settled deeply into a search for a rhyme for "silver." All in all, it looked as though a whole lot of interior monologue was going on.

It took Dortmunder about one and six-seventeenth seconds to figure out what had changed while he was away. One of the seldom used side booths, the one nearest the street door, was now occupied by a person drinking something out of a tall clear glass, revealing both ice and bubbles within, which meant club soda, which probably meant nonalcoholic. This person, male, about forty-five, who apparently still permitted his grandmother to cut his thick black hair, wore on his lumpy countenance the kind of bland inattention that did not suggest interior monologue but, rather, intense listening.

A cop, therefore, and not only that but a cop dressed in what he no doubt thought of as civilian attire, being a shapeless shiny old black suit jacket, an emerald green polo shirt and shapeless tan khakis.