In America we like our adultery straight up: a bubble of illicit passion that ends in regret. That's not what Irish novelist Anne Enright is serving in The Forgotten Waltz (Norton), which forgoes the simple morality tale for something more complex and satisfying. The novel begins as the otherwise involved Gina first sees the love of her life, the also-spoken-for Seán. Detailing the standard stuff of clandestine affairs—tawdry hotels, wife-stalking—Enright does not hide the ugliness of betrayal. But her real story is about the once illicit lovers' fraught attempt to live as a family—one that includes Seán's alarmingly strange preadolescent daughter, Evie. Casting aside cultural bromides about the immorality of affairs, Enright puts us squarely in the center of a terrible truth: Love can be miraculous—and still destroy everything in its path.