Robert Downey Jr. needs to fly from Atlanta to LA before his wife delivers their first child, but after fellow passenger Zach Galifianakis gets him not only ejected from the plane but also placed on the no-fly list, the two embark on a cross-country drive. This odd-couple comedy reunites Galifianakis with Todd Phillips, who directed The Hangover, but don’t expect anything like the other movie’s novel plotting or wild slapstick. Phillips has already directed one road comedy—the hilariously stupid Road Trip (2000)—and this is weak tea by comparison. If the story sounds familiar, you might be remembering Steve Martin and John Candy as mismatched travelers in John Hughes’s Planes, Trains and Automobiles (1987).