Sixteen-year-old Morgan decides to run away from home because her mother won't allow her to update her cell phone. She gets lost in the woods and is accidently transported to a parallel world by going through an underground tunnel. After breaking into a couple of houses for food and shelter and stealing money from the wallet of her friend's mother, she manages to locate her family in this new world. This new weight-conscious world is run by FAT (Federally Assisted Thinning) which imprisons people who go over their prescribed weight.
The story has an intriguing premise but the plot and style need to be tightened. Morgan is able to locate the version of her family that is living in the parallel world, but the other Morgan (the one who belongs in that world) doesn't make an appearance. This, plus a few other loose ends, causes the plot to lack credibility.
Regardless of the slight weakness in the plot, it remains an entertaining story geared for the tween audience.