The separate apartments were once a single unit; all that remains is a decapitated staircase winding to the ceiling. As the rightful owners of both floors and as two people who'd like to make a baby, Alex and Nancy wish Mrs. Connelly would move out. Instead of consulting a lawyer or talking it over with their real estate broker (Harvey Fierstein), they decide to knock her off. But "Duplex" is too cute and too forced to let sinister desperation get the best of it.
When the couple move in, Alex has six weeks to finish his second novel. But he can't get far because Mrs. Connelly is often urging him to be her companion. He obliges, going with her to the pharmacist and the bank and the grocery store. Even if he wanted to stay at home and write, he'd just pass out from exhaustion. And their neighbor's habit of sleeping with the TV on at THX volumes means a slew of restless nights for Alex and Nancy. In the movie's only inspired gag, Alex surreptitiously installs Mrs. Connelly's set with the Clapper, after which he finds himself embroiled in a riotous clap-off with her.
The movie extinguishes every plot the couple cook up. Danny DeVito directs from Larry Doyle and John Hamburg's screenplay, and it's hard to think of a black comedy that backs off from its diabolical urges the way this one does. DeVito seems to have merely commissioned a predictable script that combines the two unhappiest comedies he's directed. The writing grafts the quasi seniorphobia of "Throw Momma From the Train" onto the lethal house skirmishes in "The War of the Roses." The result is a cheap and cloying contraption that doesn't know when to stop smirking.
"Duplex" also doesn't know what to do with its supporting players. The squandered include Wallace Shawn, Justin Theroux, Swoosie Kurtz, and Maya Rudolph. Even Amber Valletta, as a ridiculously thin mother-to-be, feels wasted. Only Robert Wisdom has some fun playing the neighborhood cop who holds Alex and Nancy in contempt. DeVito clearly has lost interest in replicating the bleak heartlessness of "War of the Roses." The movie's not exactly optimistic -- it's often quite mean, in fact, but witlessly so. A nasty thriller lurks amid the pratfalls and screwballing: What, for instance, are we to make of Mrs. Connelly's peering in on a lovemaking Alex and Nancy?
Most of Alex and Nancy's attempts to do in Mrs. Connelly feel like old episodes of "Tom and Jerry." See Alex blown across Mrs. Connelly's apartment by her stove. See Nancy eat a mouse dropping mistaken for a raisin.
Excusing the passage in which a hitman (James Remar) whom the couple hires tries to polish off their neighbor, "Duplex" is almost harmless enough to take the kids. They'd get a lesson about gentrification (yuppies, don't mess with grandma). And they'd see Stiller and Barrymore make big goofy faces, as though "Sesame Street" had sponsored a toothless real-
estate farce.
**
Wesley Morris can be reached at wmorris@globe.com.
