FROM THE START, it's clear how Life as We Know It is going to play out: A well-off couple, Peter and Alison (Hayes MacArthur and an all-too-brief Christina Hendricks), die suddenly in a car crash, leaving behind a baby daughter, Sophie (triplets Alexis, Brynn, and Brooke Clagett). Their best friends Holly (Katherine Heigl) and Eric Messer (he goes by just "Messer," played by Josh Duhamel) are the child's godparents, but had never been informed that their friends' wishes were that they—as in, both of them—get custody in the event of Peter and Alison's deaths.

Of course, Holly and Messer hate each other, after having met on a disastrous blind date that Messer completely blew, in an unnecessary opening sequence that is puzzlingly out of sync with the character we later come to know. They bicker like siblings when they see each other at occasions like their friends' wedding and Sophie's first birthday, but—thrown together into sudden parenthood, in their friends' big house, even—they play mommy and daddy long enough to fall in love, just like we knew they would.

This is a film without surprises. Its characters are squeaky clean, whiter-than-white upright citizens who only very rarely bake pot brownies or hire a cab driver to babysit. But unpredictability isn't really on the table here. The point is to take the story's ride, and to make your pride accept the tear-jerk moments as these characters mourn their friends and accept the responsibilities their lives have been built around avoiding. Doing so is made possible because Holly and Messer perform in an acceptably complex, heartfelt manner that minimizes the droll necessity of new-parent cinematic hijinks. The goofy stuff (Baby poop on the face! Baby poop in the hat!) is limited to a tidy, short chapter that's quickly dispensed with before the film goes ahead with the complicated stuff.

Life isn't a spectacular or brilliant film, but it does demonstrate how achievable it is to make a moving romantic comedy that asks you to suspend your disbelief without insulting your intelligence. And that, these days, is remarkable.