The perfect Mormon wife in the perfect Mormon town has a secret: she doesn't believe in God. Her husband has a secret, too: he's in love with another man. She's stood by her husband for two years, tending their secrets, fading into the easy background of Rexburg, Idaho. But when she meets a man who calls himself "X," an untidy, beer-drinking artist on a rambling sabbatical through the Western States, her resolve to be the perfect wife finally crumbles.

At first her affair with X is just another secret to keep. He'll be gone soon, and no one will be the wiser. But she quickly realizes she can no longer be content with the structured, wholesome life of a Rexburg woman. Though she fears her husband's reaction and the town's rejection, she leaves to join X on his journey through the Rockies.

Amid mountains and deserts, surrounded by art and creation, she discovers the realities of eternity. But just as she is beginning to build a life without religion, a death in the family pulls her and X back to Rexburg. She must return to the place that created and confined her, this time not as the perfect Mormon wife, but as something monstrous to the people she loves.