Short but certainly not sweet, this 84-minute black comedy probably wouldn't make good date-night viewing, unless a break-up was on the agenda as well. It's a mean-spirited meditation on marriage gone wrong, but worse than that, it's simply a bad film and a poor legacy for its talented screenwriter.

Hal Hartley favorite Adrienne Shelly was killed in 2006, just months before the release of her directorial debut, Waitress, which she also wrote. The script for Serious Moonlight was left behind after her death, and her husband, Andy Ostroy, sought to bring the project to the screen. Shelly's Waitress co-star Cheryl Hines makes her own directorial debut, but even her solid cast can't save this film from feeling unpolished and unfinished.

Meg Ryan (The Women) stars as Louise, a high-powered attorney who takes a break from her busy city life to relax at her country home with her husband, Ian (Timothy Hutton, Leverage). She leaves her job a day early, expecting an empty home until Ian arrives the next day. The only problem with that plan is that Ian is expecting Sara (Kristen Bell, Couples Retreat), his much younger mistress for whom he's leaving Louise.

When Ian reveals his plan to propose to Sara on their trip to Paris, Louise does what anyone would do—if he or she were crazy. She duct tapes Ian to the toilet, intent on keeping him captive until he falls in love with her again. She'll go to unbelievable lengths to keep her marriage intact, and her plan takes on a new wrinkle when a young man (Justin Long, Drag Me to Hell) arrives to rob the house.

Serious Moonlight's problem isn't the cruel interaction between two people who were once in love. When done well (see The War of the Roses and Closer), nastiness can be witty and fun. However, this film — billed as a "love/hate comedy" in its promotional materials — almost entirely lacks humor in its script. Among the four main characters — an unhinged wife, her cheating husband, his shallow mistress, and a violent robber — there's no one to identify with or laugh at. The script's other primary issue is that it feels too much like a stage play. Between its theatrical dialogue and performances, and small setting (most of the film takes place in the country house bathroom), Serious Moonlight would have been better suited to the stage, assuming it should have been produced at all.

When compared with the lovely, witty Waitress, Serious Moonlight hardly seems like it came from the same writer. Both films focus on marriages in trouble, but this film lacks the spark of its predecessor's script. There's little wit and no heart here, two elements that made Waitress such a pleasant surprise. Hines shouldn't be blamed too much for the film's problems, except for possibly being too loyal to Shelly's screenplay. There's little interesting in the direction, but that issue is barely noticeable next to the shoddy script.

Ryan is still known for romantic comedies such as Sleepless in Seattle and When Harry Met Sally, making her an interesting casting choice for this role. Her off-screen persona makes her almost worth watching here as she diverges so well from the woman audiences loved in the 1980s and 1990s. Hutton is good as well, but his character is so unpleasant that his efforts don't do much good.

Long and Bell have both proven their comedy chops in the past, but Serious Moonlight gives them little to work with. Long is alternately a little funny and a lot scary here, and the usually able and adorable Bell is just shrill as the younger other woman. It's hard to root for Hutton's Ian to end up with either woman since these awful people deserve to be alone.  

Throughout her life, Shelly fashioned an admirable career in indie film and television, both as a screenwriter and an actress. Hopefully, audiences will skip Serious Moonlight and remember the woman who made movies such as Trust and Waitress so good.