Sex, lies, videotape and prep school make for a potent brew in "Testimony," Anita Shreve's compelling tale of teenage scandal and its brutal aftermath in a New England hamlet. This focus on the kids marks a bit of a departure for Shreve, a seasoned chronicler of adult love, loss and betrayal. But then again, the event upon which the story turns leaves no one in its ever-widening path -- young or old -- untouched.

And they all have their say: the boys, the girl, the girlfriend, the roommate, the mother, the headmaster, the reporter. Shreve presents the story in character-told chapters, mostly in the first person; disconcerting at first as we struggle to parse out the timeline, it's a device that lends urgency to a story that starts out as simply sordid and devolves into tragedy.

The students at Vermont's Avery Academy are a heterogeneous lot, a mix of brilliant kids destined for Brown and Juilliard, local farm boys who happen to play good basketball and post-high school athletes bringing up their GPAs to qualify for college. It is basketball that brings together three upper-class boys and a 14-year-old girl in a dorm room one January night after a disastrous game and an alcohol-fueled dance. It might only have been a regrettable night, were the goings-on not captured on camera and posted on the Internet.

Shortly after, a tape lands in the possession of headmaster Mike Bordwin, who watches it in sick disbelief, not yet knowing the role of his own moral failings in what he is seeing. This stunning scene, in the book's first pages, plunges us immediately into the mess; and although the story begins and ends with the teenagers, it is the bruised grownups -- Bordwin in particular -- who resonate most profoundly.

Perhaps that's because Shreve has trouble writing in a believable adolescent voice. She makes a stout effort with varied syntax (as she does to distinguish all the characters), but the kids' stories all have a similarly stilted air. Shreve fares much better with characters who could be her contemporaries.

But this is a minor distraction in an otherwise can't-turn-away tale that examines how, in the words of one boy's mother, "A single action can cause a life" -- and a town, a marriage or three, and several careers -- "to veer off in a direction it was never meant to go." "Testimony," indeed, takes us in unexpected directions, from disgust to heartbreak and, ultimately, a hint of redemption.