All of Erin's life, her older sister has eclipsed her, stolen her boyfriends, and commanded the family's attention with one meteoric crisis or another. Meghan was always smarter, prettier, more daring and dynamic. As a child, she could charm her way out of any situation, usually leaving Erin to shoulder the blame for their various transgressions. But Meghan has been gone for years, and now Erin is eager to leave Butte behind her, too: to go east to art school or west to Los Angeles to become a jewelry designer-anywhere, so long as it's far from Butte, Montana. Then Meghan, a single mother with a six-year-old daughter and an infant, unexpectedly returns, again expecting Erin and their mother to solve her problems. But this time there are other people involved, no easy solution to those problems, and no one else to blame.

Meghan, still beautiful and magnetic, is now addicted to men, danger, and drugs. She is the world's "most frequent flier." Little Teensy and baby Si-Si are lonely and endangered. Teensy, especially, has been affected by her mother's neglect, and she clings to Erin, desperately craving the intimacy and affection that has been denied her. When Meghan's attempts to stay clean falter, the responsibility for the children becomes Erin's. But how much can she be expected to sacrifice for her nieces' well-being? Can she find fulfillment and happiness, even in Butte?