Caution: spoilers.

I hated reading The Girl Next Door by Jack Ketchum. I did not enjoy it at all. If Ketchum were not the craftsman he is, I’m not sure I could have finished it. As it is, he is an astonishing writer and he knew exactly what he was doing with this book. And it’s an important book, and, I think, one that should be read, and talked about. The back description sums up why: “Based on a true story, this shocking novel reveals the depravity of which we are all capable.”

Based on a true story. The novel is a fictional take on the true story of the horrible abuse and murder of Indiana teenager Sylvia Likens. Sylvia was abused, imprisoned, and eventually killed by Gertrude Baniszewski, whom Sylvia’s father trusted with her care. Baniszewski involved a handful of neighborhood children and her own children—Sylvia’s peers—encouraging their participation in inflicting serious injuries on Sylvia. Several adults in the neighborhood saw hints of maltreatment but none of them called authorities. The abuse escalated to shocking degrees, and eventually, Sylvia’s murder.

Knowing this book is based on a true story makes it that much more difficult to read. Because unlike two similar difficult-to-read-but-masterful books—American Psycho by Bret Easton Ellis and Not Forever, But For Now by Chuck Palahniuk—this is not a satire. It’s an exposé.

Ketchum’s book takes a hard look at the questions: How could this happen? Why did it happen? By his own admission, he flinched. In the book, main character David is redeemable, and Meg (the fictional version of Sylvia) has some small comfort at the end—she is not alone.

The depravity of which we are all capable. Several of the villains in this book are kids. The youngest is 10, the others in their early teens. However, their youth does not render them inculpable.

Ketchum makes David, neighbor boy and family friend, our protagonist. In doing so, he takes away our easy out—letting the kids off the hook and blaming only Ruth. David knows his limited participation is wrong, and he understands that his passivity is tantamount to betrayal. He approaches his parents when the abuse begins to escalate, but does such a poor job of explaining what is happening—and his parents such a lousy job of listening to him—that it amounts to having done nothing.

We are not to walk away from this book thinking, aw, he’s just a kid. We are to see ourselves as David. We are challenged to confront our own hesitation to take a stand when it’s difficult to do so, when we feel (or are) powerless, and when we might lose standing in our peer group—including in our careers or at university, for example.

Ketchum’s Ruth, the fictional Baniszewski, has had a rough and unfair life, and she has lost her ability to empathize. She convinces herself, at least in the beginning, that she’s helping Meg avoid some of the perils to which she herself fell prey. She is as hateful as any character I’ve ever encountered in literature.

While we might be very unlike Ruth, still: How many times have we justified being unkind, callous, or thoughtless because we perceive someone else’s suffering as less than our own?

Have we gloried in someone’s misfortune because we think they deserve it?

Have we labeled a group of people—those who vote differently than we do, for example, or those who choose different lifestyles—and by labeling them, rendered them less than human, a group we can denigrate and even persecute?

An important point to bring away from this book: Don’t assume you can never be the monster.

“We had permission.” A key factor both in the fictional and the true stories: The neighborhood children participated in torturing a girl because they were told they could. They had permission. An authority figure told them it was their right. They felt justified. They felt righteous. They might as well have confidently stated that they were “on the right side of history.”

So here’s another point: We can’t be like children and assume that authority is always right. “I was just following orders” didn’t keep war criminals from punishment. “They told me it was the right thing to do” doesn’t absolve us from asking questions. We have an obligation to defy authority when authority acts to persecute, vilify, and dehumanize. And no, it’s not just those people over there who need this lesson. It’s us, too. Whoever your “us” includes.

I needed some comfort while I was reading, some support. I posted about this reading experience in the Facebook group Books of Horror—an excellent community of well-read fans of the horror genre. The responses were thoughtful and considered. Other readers talked about feeling complicit in the atrocity just by continuing to read about it. They talked about honoring the memory of Sylvia Likens by reading the fictional account of what happened to her—giving her a voice and seeing her. A few people didn’t finish the book. A few people did and were still shaken. Very few were untouched by it.

This isn’t a book I’m going to be giving away at Christmas. It’s a difficult read. In writing this book, Jack Ketchum reminds us: We must confront the potential monsters we carry inside ourselves.