Envy may not be a likeable or entirely amusing flick, but it’s an intriguing dark comedy with an important lesson about the green-eyed monster within all of us. Co-starring funnymen Jack Black and Ben Stiller, this movie shows what can happen when jealousy over the good fortune of others is carried to the max. Black and Stiller deliver surprisingly intuitive performances as neighbors and best friends who try to remain close after one of them becomes outrageously wealthy.

Tim (Stiller) is consumed with envy when Nick’s (Black) invention, “Vapoorizer,” creates a buying frenzy among dog owners. Spraying this product on dog poo makes those smelly droppings disappear instantly. Why didn’t Tim invest a measly $2,000 in Nick’s invention when his friend gave him the opportunity? That’s what Tim keeps asking himself. And so does his unhappy wife (Rachel Weisz). In their place, I would be envious, too. Nick wants to stay near Tim, so instead of moving to a more expensive neighborhood, he builds a residence rivaling the Taj Mahal on the site of his old house. He also installs a merry-go-round in the yard for his children and buys them a beautiful white horse as a pet. How could one not be jealous of such wealth when it’s shoved in your face like this every day?

Stiller (Starsky & Hutch) displays acting chops I didn’t know he had here, especially during scenes where his character attempts to hide his true feelings from his friend. You can tell Tim is about to burst -- and when he does, terrible things happen. One of the worst involves meeting an eccentric bum (the always amazing Christopher Walken) in a seedy bar.

In contrast to Stiller’s dark performance, Black (School of Rock) glows like a ray of sunshine as Nick, a cheerful man basking in his new-found wealth. He walks across the golf course oozing confidence; he presides over gourmet meals like a priest offering up communion; he wears his expensive new wardrobe with pride and delight. Because Black endows his character with a childlike innocence, I didn’t get the feeling Nick meant to provoke his friend on purpose. When his wife (SNL’s very funny Amy Poehler) decides to run for political office, Nick's own troubles begin -- and he turns to guilt-ridden Tim for help.

Judging from the way my husband and I chuckled quietly during most of this movie, Envy will no doubt appeal to viewers with an offbeat sense of humor like ours. However,  some moviegoers might be disappointed by the serious nature of this modern morality play. Still, who can resist Jack Black in a flamboyant cowboy outfit astride a rearing white horse? Eat your heart out, Lone Ranger.

(Released by DreamWorks and rated “PG-13” for language and sexual crude humor.)