Save for an exquisitely bittersweet coda, Jeffrey Eugenides' 1996 short story "Baster" closes with the bathroom shenanigans that give The Switch its title, leaving the movie to take a full hour's worth of creative license. But the two versions part ways well before the point where Eugenides' story ends and the movie continues, and their different handling of that pivotal scene says everything about where the adaptation went terribly, inexplicably wrong.
First, a little background: Wally and Kassie (called Tomasina in the original) are former lovers and current best friends, played in the film by Jason Bateman and Jennifer Aniston. With her biological clock ticking and dim prospects for a long-term relationship, Kassie resolves to find a sperm donor, a process that has her eyeing candidates like prime cuts of beef.
Stung that he's not on the genetic shortlist -- he's an egghead, but neurotic and short -- Wally is stung further when Kassie throws an "I'm Getting Pregnant" party with prize pony Roland (Patrick Wilson) as the guest of honor. So in a fit of pique, he slips into Kassie's bathroom and replaces Roland's sperm with his own.
Now here's a little more background: In Eugenides' story, Wally had gotten Kassie pregnant during their time together and she had an abortion -- one of three in her life, in addition to a fourth pregnancy that ended in a miscarriage. Wally had always wondered what their child would have looked like, and making the switch was an act of extreme passive-aggression, with results both intended and sad. In the movie, the bathroom scene is a zany comic set piece, with a raging drunk Wally accidentally fumbling Roland's sample before replacing it. The next morning, he doesn't even remember what happened.
Filmmakers are entitled to take liberties with source material, of course, and in a case like "Baster," where the story ends in Act One, it's essential. But screenwriter Allan Loeb and Blades Of Glory directors Josh Gordon and Will Speck are so determined to pry a romantic comedy out of Eugenides' acrid little story that they wind up gutting it completely.
Absolving Wally of any responsibility in replacing the sperm sample may make him easier to like, but it also buffs out a thorny, complicated and not altogether irredeemable soul. In his place is the typical Bateman Everyman, put-upon and likable, but imported from a dozen other movies.
What's left of The Switch is a lot of cute/mawkish scenes of Wally, seven years later, bonding with the nerdy little scamp (Thomas Robinson) he'll eventually discover to be his son and vying against the genetically superior Roland for Kassie's heart.
It all works out agreeably enough, albeit in strict adherence to rom-com formula, right down to the obligatory wacky-best-friend roles given to space cadets Jeff Goldblum and Juliette Lewis. But on the road from page to screen, Eugenides' richer, more troubling story got swapped out for an agonizingly conventional one. And the filmmakers presumably weren't drunk when it happened.