Getting out. It's something that Billy (Jesse Eisenberg) has thought a lot about in Lucy Thurber's Scarcity, a dark comedy about family dysfunction that opened last night at the Atlantic Theatre Company. Before being transferred to honors classes at his high school, Billy used to be able to do this like his father, a few beers with friends and hanging out around town. Now, though, he finds that he doesn't fit in with his more wealthy classmates, and the kids he used to hang with, well, they just end up in schoolyard brawls. Billy's only exit strategy - as far as he can see - is having his teacher, Ellen or Miss Roberts (Maggie Kiley), help him get into a private school, somewhere far from home.

Given home - a rundown apartment somewhere in Western Massachusetts (brought to life with vivid grit by scenic designer Walt Spangler) - Billy's plan may not be a bad one. Dad Herb (Michael T. Weiss) is routinely brought home by a local cop Louie, who just happens to be cousin to Herb's wife, Martha (Kristen Johnston). While Herb doesn't work, Martha is a waitress, and her salary, supplemented by foodstamps, allows the family, which includes Billy's precocious younger sister Rachel (Meredith Brandt), to survive. When things get tight, though, Louie (Todd Weeks), steps in with a few bags of groceries or a check for a utility bill. This galls his wife Gloria (Miriam Shor), who, along with Herb, thinks Louie and Martha are having an affair. As if Martha's relationship with her cousin were not a big enough elephant in the family's cramped apartment, Herb, who has a tendency toward alcoholic blackouts, might have been (or might be) sexually molesting Rachel.

It's an unattractive world to be sure, yet somehow, Thurber illuminates not only the pathos of Billy and his family's world, but also the humor of it, a duality beautifully highlighted in Jackson Guy's heartfelt production. With the exception of an uncomfortable moment in the second act, when Thurber attempts to demonstrate how sins of the father are visited upon the son, Scarcity boasts an honesty that is pungently compelling.

This trait is due, in large measure, to two fine central performances. Eisenberg makes Billy a teen who is simultaneously wired and edgy and slacker. Though one's never quite sure where this young man might go next, Eisenberg ensures that audiences never lose sight of Billy's keen intelligence. Equally impressive is Johnston's performance as the wildly mercurial Martha. One minute cooing, the next minute growling like some fierce beast, Johnston's Martha, like Eisenberg's Billy, is never anything less than riveting, particularly as she and Herb (played with exceptional kindness and dignity by Weiss) navigate their ambiguous love-hate, passive-aggressive relationship.

Early on Weeks (as Martha's chipper cop cousin) provides a certain relief from the dreariness found in this home, but even he and Shor (as Louie's put-upon, and sometimes put-down) wife, bring a measure of darkness into the world from which Billy must escape. Perhaps what's most impressive about Scarcity is the fact that rarely do theatergoers feel a similar need.

Scarcity continues through October 14 at the Atlantic Theatre Company (336 West 20th Street). Performances are Tuesday through Friday at 8pm; Saturday at 2 and 8pm and Sunday at 3pm. Tickets are $55.00 and can be purchased by calling 212-279-4200. Further information is available online at www.AtlanticTheater.org.