Washington all but rolls up the sidewalks after midnight, culturally speaking. So the scrappy Source Theatre decided to liven things up with its Late Night theater, a series of offbeat, one-act plays that attract a loose, spontaneous, bring-your-own kind of crowd. Source is now trying to generate after-hours activity in both of its houses with two short comedies, "The Nature and Purpose of the Universe" and "Clone."

At the Warehouse Rep is Christopher Durang's "The Nature and Purpose of the Universe," unquestionably one of the notorious satirist's cruelest, most objectionable -- and funniest -- works. Perhaps because his plays are more like skits, with dramatically sophisticated ideas and somewhat crude execution, Durang plays best in humbler environs (Source's long-running "Beyond Therapy" was more viscerally funny than Arena's glossy, distanced version). His is the kind of dark humor that makes you glance around, guiltily, after a sudden outburst of laughter, just to make sure no one is staring suspiciously at you.

Here, as in his "Sister Mary Ignatius Explains It All for You" (which is all but unproducible because the mere mention of it on a season schedule brings out the pickets), Durang tackles the dual dogmas of Catholicism and the Nuclear Family by presenting the unrelenting persecution of Weehawken, N.J., housewife Eleanor Mann.

Eleanor's husband ignores her, and of her three sons, one is a pimp and drug pusher, another is homosexual and the third has been sexually mutilated in "a bizarre reaping accident." All of them beat her. And her household appliances don't work. Yet Eleanor hangs on to the belief that "suffering is the will of God." Watching over this domestic carnage is a pair of "agents of God," one of whom serves as a kind of "Masterpiece Theatre" narrator while the other steps in to interfere in the Manns' lives.

Of course much of this -- or most of it -- is reprehensible, but that's what makes it work, and if you're the type to show up at a 14th Street theater at this hour it probably won't rattle you too much. Jim Stone directs the 70-minute piece like a segment of "Mary Hartman, Mary Hartman" on angel dust, a violent burlesque, and he understands Durang's theatrical panache, making a coup de theatre out of a vacuum cleaner turning on unexpectedly. All the performers go full-out, particularly Brilane Bowman, whose perfectly potato-faced lassitude as Eleanor is hilariously bathetic. (Bowman also choreographed the alarmingly realistic fights, of which she is usually at the receiving end.)

Down the street at the Main Stage, Michael T. Folie's sci-fi spoof "Clone" is suffering from an energy drain. The Washington playwright intends to provide a comic view of the Craven New World to come, but it's all talk, no action.

The hour-long "Clone" concerns dying, decrepit billionaire Ronald Edgar Dowling (one of the last remaining "natural" births) and his grasping, eternally young wife Sugora Kane (a "splice"). Due to community property laws in the year 2019, Sugora will not be able to reach her husband's assets after his demise, so she plots to copy his memories and thoughts into a younger, sexier clone of himself.

Folie has some interesting ideas, but never takes a point of view. Director William Freimuth previously has proven his outre' sensibility with stuff like the gloriously gory "Titus Andronicus," but does relatively little with this material, which seems to scream for excess in everything. Only Keith Parker, as the ranting, red-faced Dowling, obliges.

The Nature and Purpose of the Universe, by Christopher Durang. Directed by Jim Stone. Lighting design by Michael Matthews and Jim Stone. With Brilane Bowman, Craig Bradshaw, Todd Clark, Scott Davis, Patty Hardee, Thom Hofrichter, Shane Mayson, Bill McKenney and John C. Reed. At the Warehouse Rep, Fridays and Saturdays at 11:30 p.m., through Dec. 19.

Clone, by Michael T. Folie. Directed by William Freimuth. With Jane Beard, Jim Hicks, Keith Parker, Ritchie Porter. At the Main Stage, Fridays and Saturdays at 11:30 p.m., through Dec. 19.