Nobody ever sits down for a proper meal in Picnic, the Roundabout Theatre Company's Broadway revival of William Inge's 1953 Pulitzer-winning drama. But other appetites aren't as easily ignored when a handsome young drifter, Hal (Captain America's Sebastian Stan), starts doing yard work for the neighbor of a small-town single mother (Mare Winningham) with two daughters: Madge (Taken 2's Maggie Grace), ''the pretty one,'' and Millie (Madeleine Martin), the plain tomboy. Madge is already going steady with the nebbishy Alan (Ben Rappaport), who happens to be Hal's former fraternity brother, but the laws of nature (or is the The Soap Network?) dictate that two kids as wild of heart and high of cheekbone as Madge and Hal can't stay apart for long.
Director Sam Gold does a swell job of conjuring the fabled American epoch when people used the word ''swell,'' that post-War pre-irony era of five-and-dimes and paperboys and town halls. The set is a lovingly worn-in prairie house illuminated as much by the glow of nostalgia as by stage lights, and the cast dives headlong into the earnest melodrama of Inge's script, which is better at conjuring memorable characters—like the attention-starved neighbor (Ellen Burstyn) or the lovelorn schoolteacher/lodger (Elizabeth Marvel) than at knowing what to do with them once they've said a few pithy lines on the porch.
If there's a tear in all the gauzy wistfulness, it's the 21st-century flavor of Stan and Grace, who hit their characters' emotional marks with enough TV-ready precision to stamp out any pesky nuances. And when Stan swans around the stage bare-chested, with a torso as tautly rippled as a tufted leather sofa and his jeans slung anachronistically low, there's no sense pretending the play is shooting for period accuracy. It's simply trying and occasionally managing to recapture the thrill of molten hormones, the heat of an endless summer day, and the dizzying rush of a first love that could happen anywhere, anytime. B+