Pale, lanky Zach spends the movie's first 20 minutes loitering wanly, swaddled in his miniature, multicolor security blankie, uncertain about how to get his life jump-started and perhaps wondering if he even wants to. Imagine his surprise, and his dismay, when he learns that Beth has reappeared at her parents' house, looking perky and normal in a dotty white cotton dress — at least, as perky and normal as a character in a dotty white cotton dress can look. Beth's mom is delighted: "She's my baby girl! She's resurrected! It's a miracle!" she cries out with maniacal joy, which is just the first clue that something is terribly wrong with this revivified, vaguely zonked version of the girl they used to know. The second or third or fourth clue, if you're counting, is that Beth suddenly becomes crazy about the local smooth jazz radio station, whose stupefying noodling permeates the movie from there on out.
Scene by scene, Baena (who, with David O. Russell, co-wrote I Heart Huckabees) builds a bizarro world in which deranged mailmen drive on the sidewalk, and dust-covered, dead grandpas reappear to scare the bejesus out of their kids and grandkids. Except it's not quite as crazy as it needs to be: There's something listless about Life After Beth — it starts out as a reflection on the potentially morbid nature of grief and then doesn't seem to know where to go. Before you know it, Plaza's Beth is blood-smeared and growling and chained to a stove, a vision that's just nutty enough to be funny — but only for about 30 seconds.
Life After Beth might have worked simply as a vehicle for Plaza, who, with her Campbell Kid eyes and wickedly juicy smile, truly seems game for anything. She was dazzling in last summer's The To-Do List as a recent high schooler who sets out to perfect her sexual prowess before heading off to college. Plaza comes off as a bit of a nut, in the good way, but she always knows when to pull back: Contemporary comedy written for women sometimes leans a little too hard on self-humiliation for laughs, but Plaza — unlike, say, Melissa McCarthy — knows instinctively where the cutoff is, never veering into self-abasement. But Life After Beth doesn't serve her well. She's funny enough in the early moments, when her living-dead randiness takes Zach by surprise. But before long, there's nothing left for her to do but mewl and roll her eyes. At that point, it's up to DeHaan to sustain the movie, and he can't quite do it: He's transparent, figuratively and almost literally. Zach is a kid who's just drifting through life, but DeHaan doesn't give him much shape, texture or tone — he's the color of water and just as amorphous.
When Life After Beth works, it's usually because of some silliness from the supporting cast. Anna Kendrick shows up, all too briefly, as a potential new love interest for Zach — she's like an adorable and extremely nervous bird. Shannon's intentionally manic, overprotective mom is as scary and over the top as any of the zombies, and probably more so. Paul Reiser, as Zach's dad, gets a few great Borscht Belt moments with his own father (Garry Marshall), who comes back from the grave to kvetch and be a nuisance. But John C. Reilly, in his olive-drab dad shorts and terrible matching socks, may be funniest of all, not because of anything he says but just for the way he embodies pure, fatherly befuddlement. All he wants to do is to keep peace in the household, impossible when your teenage daughter is a zombie. His Droopy Dog demeanor keeps the movie going, even when those pesky undead corpses threaten to drag it down. Reilly should have a zombie movie of his own: You could call it Dawn of the Dad.