Zack and Beth's relationship has never been so good.

Before she died, the titular heroine of Life After Beth had broken up with her overly needy beau, telling him she needed to see other people.

What a difference an unnatural death makes!

That's right, Beth is a teenage zombie and Zack, well, he's the boy who won't let a little rotting flesh get in the way of love.

The latest in the ever-growing zombie horror rom-com subgenre, Life After Beth is the directorial debut of screenwriter Jeff Baena, who cowrote David O. Russell's brilliant 2004 comedy I Huckabees.

Featuring an awe-inspiring, stellar performance by Parks and Recreation's (and Wilmington's) Aubrey Plaza as Beth, the film opens with the high school girl's short-lived death. Having dumped Zack, she's out on a solo hike when she's struck down by a snake.

Zack (Allentown's Dane DeHaan) is beyond consoling. He won't eat. He won't sleep, and he won't take off Beth's favorite skiing scarf - in the middle of the summer. He hugs the scarf, smells it, tastes it, and in one scene holds it awfully close and fast to his nether regions.

"You're [bleeping] a scarf," Zack's bullying older brother Kyle (Criminal Minds' Matthew Gray Gubler) screams when he walks in on his kid brother.

Cheryl Hines and Paul Reiser, two in the film's terrific troupe of supporting players, are wonderfully hateful as Zack's less-than-understanding parents, who suggest his behavior is due to a brain injury and insist he get a CAT scan.

Far more loving are Beth's parents, Maury (John C. Reilly) and Geenie (Molly Shannon), who console the boy over games of chess. Then, when Beth suddenly shows up - animated, if not alive - they encourage him to court her again.

Beth, who has no memory of the days leading up to her death, is a transformed young woman: She can't get enough of Zack. She just wants to ravish him. Ravage him. Eat him up.

Things start going wrong when Beth begins having violent mood swings. Zack is patient, understanding. But even he begins to have doubts when he sees that she has covered every surface of her attic bedroom with thick layers of mud. ("She's building something," her dad says with delight as Beth digs up more dirt from the garden and carries it up the stairs.)

An uneven creation, Life After Beth is at its best when Baena gives Plaza room to do her crazy, sublimely perverse thing. But halfway through, the story loses momentum, becoming a listless, predictable Saturday Night Live skit.

Some of the problem lies with timing: Baena wrote the film in 2003, at the height of the zombie-comedy revolution that produced Shaun of the Dead, Tokyo Zombie, Poultrygeist: Night of the Chicken Dead, and Zombie Strippers.

Today, it feels dated, if not entirely dead.

Life After Beth **1/2 (out of four stars)

Directed by Jeff Baena. With Aubrey Plaza, Dane DeHaan, Molly Shannon, Cheryl Hines, Paul Reiser, John C. Reilly. Distributed by A24.

Running time: 1 hour, 31 mins.

Parent's guide: R (pervasive language, some horror violence, sexual content, nudity, brief

drug use).

Playing at: PFS at the Roxy.