From blinkered fundamentalism to artistic hypocrisy to the concept of a “just war,” the formulaic but intellectually ambitious hostage drama “The Caterers” has a lot of interesting things on its mind. Unfortunately, playwright Jonathan Leaf struggles to get those things into the mouths of plausible characters.

A new biopic of Mohammed is about to premiere, and David and Nina Weintraub (Ian Blackman and Judith Hawking), two caterers and struggling writers, are using the screening room’s cramped upstairs vestibule as a staging area for their food preparation. But Islamic law forbids the depiction of Mohammed in any way, and a gun waving Arab terrorist (Brian Wallace) arrives to confiscate the print of the offending film. The three are soon joined by the film’s fatuous British screenwriter, Warren Heath (Peter Reznikoff), who becomes a central target of the terrorist’s ire.

If the scenario sounds familiar, that’s because it actually (sort of) happened. Several Washington, D.C., buildings were held under siege for two days in 1977 in protest of a filmed treatment of Mohammed’s life. None of the 120 hostages were killed (although one reporter did die), and the film quickly slinked off to critical and commercial failure.

But Mr. Leaf, an occasional contributor to The New York Sun, has changed the setting to here and now. And I mean now: The terrorist, who also calls himself Mohammed, cites Western depredations that include not just reality TV and Abu Ghraib but the aftermath of Hurricane Katrina. And while Mr. Leaf’s scenario is considerably less sprawling – the action is confined to one terrorist and three hostages – there’s no guarantee that this story will end quite as happily.(This Immediate Theater Company production is being staged at the home of the visceral 29th Street Rep, and Dan Deming’s efficient fight choreography fits in well with the house company’s brutal aesthetic.)

Nina converted to Judaism when she married David, and has the zeal of a convert, which allows Mr. Leaf to pit her and Mohammed against each other for numerous political confrontations The French-speaking, mildly self-deprecating Mohammed falls firmly in the “we are not so very different, you and I” school of fictional foreigners, although Mr. Leaf does add the curious complication of his outsized libido. Warren is easily the least likable character here, but he’s also the least believable: Mr. Reznikoff’s brisk British readings don’t come close to transforming this limousine liberal (are the left leaning plays and shaggy hair meant to evoke images of David Hare?) into anything like a real character.

Mr. Blackman and Ms. Hawking, however, nail the marital familiarity between David and Nina. Of the three hostages, Nina is by far the most intriguing, due in no small part to Ms. Hawking’s sharp, inventive performance; when we do find ourselves pulled into their horrifying situation, it’s usually because of something she says or does. And Mr. Wallace evades the pitfalls of all but the most unplayable of his scenes, giving Mohammed an urbane charm that (almost) always transcends the role’s innate stereotypes.

For every insightful comment or perceptive performance, though, “The Caterers” has at least one ill-considered leap of logic. Extremely frightened people do strange things, but mock an armed fundamentalist terrorist during his prayers? Or say things like “chopchop” and “let’s pull up our socks”? And are we to believe that the flimsy closet door is soundproof, which means the people locked into it aren’t privy to what’s going on in the main room? None of these flaws are crippling, but they give the audience a chance to slip out of the play’s real-time action and see the creaky structure for what it is. Plays of ideas are in distressingly short supply these days, but it takes more than ideas, even intelligently articulated ones, to make a successful play. “The Caterers” is certainly the most topical play in town. But getting somewhere first doesn’t always make you the winner.

Until October 30 (212 W. 29th Street, between Seventh and Eighth Avenues, 212-868-4444).