C

The makers of “The Switch” deserve credit for trying to do something different in the rom-com genre. It’s unfortunate that their effort is based on such an unpleasant premise. Even though the picture rallies in the second half—due not to the relationship of the adult leads but to that between the guy and a son he never knew he had—it’s never able to overcome those opening reels.

Allan Loeb’s script, fashioned from a story by Jeffrey Eugenides, has a first act that aims at a Woody Allen vibe, in which sad-sack, whining New York exec Wally Marrs (Jason Bateman) clearly pines after his best bud Kassie Larson (Jennifer Aniston), who sees him as a pal rather than a romantic possibility. Wally’s grumpy repartee is clearly intended to mimic Allen’s old diatribes, but it’s difficult to call it an apt comparison when his narration begins with the groan-inducing observation that we’re called the human race because we’re always in a rush. When that’s the sort of supposed witticism a writer chooses to start with, one has just cause to worry about what’s to follow.

Things don’t improve at all when Kassie, hearing the biological clock ticking, decides to have a child by means of artificial insemination and refuses even to think of Wally as a possible donor. To his chagrin she instead chooses studly professor Roland (Patrick Wilson), a handsome nonentity whom Wally instantly loathes upon meeting him at the “insemination party” Kassie’s free-spirited friend Debbie (Juliette Lewis) throws for her. In response, he gets totally blotto on booze and drugs, accidentally spills Roland’s sperm sample and replaces it with a donation of his own. (This sequence is intended to be amusingly goofy, but it actually comes across as bizarre and rather unsettling.) Of course, he’s so zonked out that he totally forgets the whole episode, and when Kassie moves back to Minnesota, they lose touch.

Flash forward seven years. Kassie returns with six-year old son Sebastian (Thomas Robinson) in tow. The tyke is miniature version of Wally, a dour little hypochondriac who sees the worst in everything and whose unchildlike hobby is collecting picture frames with the store photos still in them. In time, of course, Wally works out the truth and bonds with the kid. But by then Kassie has contacted Roland and the two are off on a whirlwind romance. How can Wally tell her what happened and win her away from the other man?

What rescues this second half of the movie, at least to some extent, is Robinson. True, Sebastian is a total conceit—one of those urchins that talk like tiny adults and are impossibly mature for their years. You’ve seen them on plenty of bad sitcoms. But though the character’s a cliché, Robinson, with his plaintive voice and eyes so saucer-like that he’s almost like a figure out of Japanese anime, makes the kid sympathetic, and he works nicely with Bateman. That’s more than can be said for Bateman’s scenes with Aniston, who despite her top billing is pretty much wasted here doing her usual about-to-bawl shtick.

There’s a bit more good news in the presence of Jeff Goldblum as Leonard, Wally’s opinionated but supportive colleague. His droll delivery makes the lines Loeb provides him with sound a lot better than they actually are. By contrast Lewis mugs way too much as Kassie’s GF. And Wilson is blander than bland.

“The Switch” doesn’t do much with the New York locations, which are shot in a nondescript fashion by Jess Hall. And it doesn’t make much sense from a story standpoint, either. But though the scenes between Bateman and Robinson can’t redeem the implausible premise or the disagreeable first act, they do give the second half some affecting moments.