As with most mainstream comedies, you get nearly all of the story line and most of the best jokes in Did You Hear About the Morgans? from its trailer.

This fish-out-of-water romantic comedy about a warring upscale Manhattan couple forcibly relocated to the American heartland is marginally better than writer-director Marc Lawrence's Music and Lyrics and Two Weeks Notice, but not even the estimable comic chops of Hugh Grant and Sarah Jessica Parker can lift it above the level of ordinary. The Columbia Pictures release opens Friday.

The titular couple is Paul and Meryl, whose marriage is on the rocks because of his recent infidelity. Now Paul's desperately trying to get her back, but his attempt at reconciliation is dashed when they stumble on to a murder and are forced to enter the Witness Protection Program.

Safely ensconced in a small Wyoming town under the watchful eyes of the local sheriff (Sam Elliott) and his shotgun-toting wife (Mary Steenburgen), they find themselves gradually warming up to each other again while dealing with their cell phone-free cultural dislocation. This includes shopping at the local big-box store, milking cows, shooting guns and running away from the occasional bear. Meanwhile, they're being pursued by the vengeful hit man (Michael Kelly), who eventually shows up for the inevitable climactic shootout.

Offsetting the story's predictability is Lawrence's ability to craft genuinely funny one-liners, which are expertly delivered by Parker in a variation of her high-strung Carrie Bradshaw character and Grant with his amusingly droll laid-back manner. Happily, the Midwestern characters are not reduced to stereotypes, with Elliott and Steenburgen quite winning as the Morgans' protectors and Wilford Brimley providing some fun moments as a cantankerous cafe owner. On the minus side, Elisabeth Moss is utterly wasted as Meryl's no-nonsense personal assistant, even if she does get to show a more glamorous side than with her Mad Men character.