That Carey Mulligan is astonishing in Dennis Kelly’s one-woman play Girls & Boys is no surprise. For the past decade, Mulligan has given full-throttle portrayals in movies as varied as An Education (her Oscar-nominated breakthrough), Wall Street: Money Never Sleeps, Shame, Suffragette and Far from the Madding Crowd. Onstage she’s distinguished herself on Broadway in The Seagull and David Hare’s Skylight (for which she received a Tony nomination) and off-Broadway in a failed adaptation of Ingmar Bergman’s Through a Glass Darkly, in which she shone above the moribund goings-on around her.

What Mulligan does in Girls & Boys—a monologue by a wife and mother who has undergone a traumatizing, devastating event—is to consistently rivet us with an alternately hilarious and emotionally shattering performance, despite the shopworn material Kelly gives to her. For much of the play, this nameless woman describes her life since meeting her husband (cutely, of course, while queuing to board a flight) in a monologue that has humorous asides, as when hubby-to-be deals with a pair of gorgeous models trying to cut the queue. 

Scattered amid her conversations are scenes showing her miming everyday dealings with her two (invisible) children, in a room that—in designer Es Devlin’s clever hands—looks like a sterile dream state, everything in it a kind of cool blue that occasionally bursts into colorful vibrancy. This woman’s life moves along parallel tracks: she’s doing brilliantly at making documentaries, and she, her husband and kids make up a lovely family. Until….

When Woman describes—in exceedingly and unnecessarily explicit detail—how her idyllic life is destroyed, Kelly’s writing can’t hope to keep up with the devastating direction he wants to take to kill his protagonist’s happiness. There’s something schematic about the way her life is ripped apart, as if Kelly simply wanted to give her (and us) the most shocking thing he could think of. Even Lyndsey Turner’s initially solid direction turns soggy, as if she couldn’t figure out a plausible way to get past it. 

Whatever emotional power is wrested out of this exercise in dramatic shortcuts is due to Mulligan’s thoroughly charming, persuasive and incisive portrayal of an ordinary woman living a full life (kids, marriage, job) that’s suddenly torn from her. Mulligan gives the early light-hearted parts sardonic bite, balanced by her increasingly harried interactions with the children; when unspeakable tragedy finally rears its head, Mulligan maintains her composure and does the heavy lifting that keeps us captivated even when the writing lets her down.