I think the best books for groups to discuss are those in which the ending is deliberately ambiguous, so that every reader will have a different answer to the question “Well, what really did happen?” Or books in which the main character is faced with a difficult choice that resonates with readers no matter their age or race or ethnicity. Here are some that I’ve found work extremely well in generating heated discussion among book group participants.

Deborah Schupack’s The Boy on the Bus begins with every parent’s worst nightmare—the disappearance of your child. Only in this case, a boy who looks a lot like Meg’s eight-year-old son, Charlie, gets off the school bus at the end of the day. The problem is, he seems to be very different from the real Charlie in some definable ways (he doesn’t have asthma and Charlie did) and in some indefinable ways (Meg just knows it’s not her son). Many readers will no doubt wonder why the family doesn’t just do a DNA test to find out, but the questions the novel raises about identity are fascinating.

First-time novelist Ann Packer’s The Dive from Clausen’s Pier asks readers to consider the following question: what do we owe those we love, and what do we owe ourselves? Or, in plainer language, how much sacrifice is too much? When Carrie’s fiancé, with whom she’s just about fallen out of love, dives off the pier on Memorial Day into water that is much too shallow, he breaks his neck and will be paralyzed for the rest of his life. What should Carrie do? Readers everywhere react to twenty-something Carrie’s choice differently—some with frustration (I know someone who actually threw the book across the room in disgust when she read what Carrie decided to do), with applause, or with tears.

The paperback edition of Leah Hager Cohen’s novel Heart, You Bully, You Punk has a wonderful cover. What makes it perfect for a book group is that it poses an interesting dilemma: when your head tells you one thing and your heart another, which one should you listen to? The answer to this conundrum will change the lives of the three main characters: a teenage girl, her father, and her math teacher at the private school she attends. One question to begin with is “What does the novelist think about the role of the heart in decision making?”

Barbara Gowdy’s The Romantic asks us to consider yet another human dilemma—what it means to try to save the person we love best from destroying themselves, while knowing full well that they’re hell-bent on making that task impossible for us. Louise, who has loved Abel since both were children, must decide how much responsibility she has for ensuring his well-being when she realizes that Abel is becoming increasingly self-destructive and seems determined to drink himself to death.

Two novels by Anne Ursu make for wonderful discussions. In the first, Spilling Clarence, a chemical that causes people to remember everything in their lives infects a city’s population—and everyone has a different reaction to being bombarded by their memories. Some characters are comforted, while others find the return of the past too difficult to bear.

The second, The Disapparation of James, has an inconclusive and mysterious ending that will drive some readers crazy. Physician Hannah and stay-at-home dad Justin Woodrow take their children—Greta, seven, and James, five—to the circus for Greta’s birthday; everyone in the family is thrilled when James is selected to appear on stage as part of the last act of the evening. The magician’s final stunt is supposed to make James disappear, but it backfires horribly when James actually does disappear. Ursu takes us inside the lives of all the characters, including the magician, the policeman who is assigned to the case, and of course James’s immediate family, offering parallel realities and alternative possibilities of what really happened.

[Excerpted from More Book Lust, Sasquatch Books, 2005]