On its face, Lionel Shriver's previous novel, 2005's brilliant We Need To Talk About Kevin, seems provocative enough, chronicling as it does the events leading up to a Columbine-like massacre. Yet it's actually more daring than it sounds, since that gruesome spectacle is just the catalyst used to explore a woman's ambivalence about motherhood—which, in a society that exalts parenthood, is just as unspeakable a crime. Though Shriver's follow-up, The Post-Birthday World, retreats to the more commonplace issue of marital fidelity, it's just as honest and unsparing about its heroine's self-negating pursuit of happiness. Splintering off into two parallel universes—one in which a woman leaves her partner of nine years for another man, the other in which she stays put—the book weighs the pros and cons of passion vs. stability, and finds discomfiting truths on both sides of the equation. Typical of Shriver, it's a lose-lose situation.
As the book opens, Irina McGovern, a children's-book illustrator just this side of middle age, leads a reasonably contented life in a London flat with her long-time partner Lawrence, a devoted but bland terrorism expert at a political think-tank. Once a year, Irina and Lawrence get together with their friend Ramsey to help celebrate his birthday, but the tradition has grown rote over the years, since their only real connection to him was his ex-wife, who could no longer stand his life as a world-class snooker player. With Lawrence away on business, Irina is left to entertain Ramsey on her own, and she feels unexpectedly drawn to him, leading to a moment of temptation that sends the book careening down separate tributaries. It's a tough choice: With Lawrence, she wins the reassuring comforts of routine; with Ramsey, she gets subsumed by a hot-and-cold relationship of spectacular sex and equally spectacular meltdowns.
Shriver deliberately paints the two men in broad strokes: Lawrence, a well-educated American with informed opinions on world events and an utterly predictable set of rituals, couldn't be further removed from Ramsey, a working-class Brit with a Neanderthal's sense of decorum and a life revolving myopically around snooker. Each scenario gives her reason to suspect that the grass is greener on the other side, though readers know differently, which is less a reflection on these deeply flawed men than on Irina, who gets swallowed whole by both of them. From the start, she admits that she can't live without a man, and from that compromised position, Shriver mercilessly observes her quiet suffocation.