There will be no shortage of apologists for Date Night, the new farce starring Steve Carell and Tina Fey that leans heavily on its very hot stars to sell a very tired plot.

Don’t believe them. Carell and Fey are gifted comedians, as anyone familiar with their TV work – Carell as an oblivious middle manager on NBC’s The Office, Fey as the bright, beleagured head writer of a sketch-comedy series on 30 Rock – can attest.

They both deserve a better outing than Date Night. The chemistry between them is undeniable – dry of wit, with an engaging sarcastic edge, they play off each other nicely. But why dump them in a strained mistaken-identity thriller that fails on such a basic level to match their energy and smarts?

Here, playing a married couple from New Jersey yearning to spice up their humdrum lives, they quickly discover that boring is better. Their night on the town – a trip to New York City– is interrupted by a pair of crooked cops who take them for thieves. From there, their strange odyssey leads to a shirtless Mark Wahlberg, who aids them in their quest to get through the evening intact.

It’s a perilous journey. Trailed by gangsters and forced, in a truly embarrassing sequence, to disguise themselves as hooker and pimp, Carell and Fey do their best to elevate pedestrian material, and from time to time they succeed. Date Night is not without moments of actual humor, infrequent as they sometimes seem. But the movie suffers from multiple-personality disorder: It can’t seem to decide whether it’s a slapstick comedy, a violent caper flick or a semi-thoughtful contemplation of married life.

In all respects, it’s lacking. One wishes that director Shawn Levy (Night at the Museum and its lifeless sequel, Battle of the Smithsonian) had simply freed his stars to do what they do best – find the absurdity inherent in their plight and treat it with the lighter-than-air irony it deserves. Instead, we get car chases and gunfights, in a cheap-laughs movie with a paper-thin plot. 30 Rock forgive them; they know not what they do.