Bright colors, snappy jokes and gloriously full-bodied emotions defined Juno and Young Adult, the first two collaborations between director Jason Reitman and writer Diablo Cody. Yet Tully finds them tumbling into a chasm of overwrought metaphors.

At the center of the movie is Marlo (Charlize Theron), a 30-something suburban mother buckling under the strain of forgoing sleep night after night to comfort her crying baby daughter. Only the presence of Tully (Mackenzie Davis), an ethereal night nanny who cheerfully declares, "I'm like Saudi Arabia. I have an energy surplus," seems to siphon off Marlo's crippling stress.

Whenever Marlo and Tully chat about work, motherhood or sex, the film reverberates with haunting intimacy. It doesn't last. Tully quickly becomes condescending and cruel—the script's mean-spirited jokes mocking 21st-century suburbanites are intensely off-putting.

Then, an outlandish plot twist essentially erases the most compelling element of the story: Marlo and Tully's beautifully honest friendship.

While Marlo admits to feeling "empty," it is Reitman and Cody who are empty—of the gift for soulful yet unpretentious comedy that once made them an irresistible team.

Critic's rating: 1/4 stars.

Tully is rated R and now playing at Bridgeport, Cedar Hills, Clackamas, Eastport, Fox Tower, Laurelhurst, Lloyd, Vancouver.