In 2003, I called Laura Lippman's stand-alone novel EVERY SECRET THING one of the two best books I had read all year. It was not an easy read, as it was full of ambiguities, good people who weren't so good and really bad people who maybe weren't all that evil. Lippman examined teenage girls but not the mall-going, pop star-idolizing adolescents or the Goths or the geeks. Rather, she dove into the psyche of teenagers, trying to understand why two girls would do something truly horrific.

Lippman has continued to write her Tess Monaghan series, and I'm glad. Tess, who annoyed the heck out of me early on, is continuing to grow up and mature. She is not that far from her own teen years; I suspect she remembers high school quite clearly. TO THE POWER OF THREE, however, is a stand-alone in which one girl has shot another at their high school with a third as witness. And they were all best friends. Lippman's book gives us a chance to try to understand this meaningless act. Is it meaningless? Why would --- why do --- perfectly "normal" children shoot other kids? While it's hardly an everyday occurrence, it's far too commonplace in modern America. And most of us, whether we have kids or not, haven't a clue why it happens. Yes, some children are alienated, bullied, or neglected and made to feel like failures. But, we argue, other kids go through that and don't resort to violence. We've seen these events, from Columbine to Springfield, Oregon, and we don't begin to understand.

It's a surprise, when you think of it, that more mystery novels don't examine this phenomenon. Maybe because it is so baffling, and it probably doesn't feel like a puzzle that you can solve. Perhaps because the idea of writing about teenagers seems at once simple --- gee, how hard can it be to be a teenager? As adults, we think, "Look at all the things they don't have to deal with." At the same time, we know, we just know that we cannot understand anymore what that's like. We know and remember, often, our own hells, but none of us can say we lived in the times like Columbine.

In TO THE POWER OF THREE, Lippman brings us into the lives, hearts and minds of several people, specifically of three girls. These are fairly typical kids, living in suburban Maryland in a community that still has some farmland but is mainly a very wealthy suburb. All the girls are mainstream; all do just fine in school, both academically and socially.

One of the strengths of Lippman's writing is that in a few lines she can sketch a minor person --- the nasty piece of work, Anita Whitehead, a self-absorbed horror from beginning to end, or Kat's mother Chloe, who spends every waking moment, it seems, finding someone to blame for everything in her life. Lippman excels in the details, enough so that often I find myself going back and thinking, "Wait, did I really see that?" This may sound odd, but I was thinking of the artist Al Hirschfeld, who, with only four or five lines, could draw a completely recognizable public figure. It's not caricature, but a paring down to the essentials; Lippman can do this in words.

There are problems with the resolution of this book for me; while I understand what Perri did, I'm not sure I completely get why she acted the way she did. Perri is subtly drawn --- nothing you can put a finger on exactly, but I found her to be not what she appeared. Perhaps it was too subtle for me, but the reasons for things disturbed me.

On the whole, however, telling this story is a good thing. Those of us who read the headlines about "the victims" and "the killer" --- whether we delve into the details or not out of concern, horror, some sort of inability to look away --- never get the story. It's too often glossed over; the shooters become sick, twisted children, the victims untouchable angels. Families are either damaged beyond belief or perfect and loving. It's possible that there are situations like that, but Lippman makes us, her readers, think about it. The shooting of one teenager by another does happen for a reason, and as implausible and impossible though it seems, there are explanations for these events. Lippman has created one set of them and offers us a look. This book, like the compelling EVERY SECRET THING, made me think long after I was finished reading.