Sara and Anna Olsen awaken each morning without the comfort of their parents' love. Orphaned at a young age, they've tried their best to find a sense of safety and security within the foster system. At nine and eleven, they know more about the world than children twice their age-and it's a knowledge they have paid dearly to earn.

Inspired by true events, their story is one of survival, but it's also one of friendship, sisterhood, and hope. They must find the strength to face the world with courage and faith. Amid the tattered remains of their innocence, the sisters know that no matter what else life delivers, they can always count on each other.

When their ever-shifting world is rocked by three wood-splintering knocks on the door one cold, autumn night, the sisters flee into the darkness, alone and terrified. What could drive them into the frigid night air? On that night, Sara makes a promise to her sister, one she spends her whole life trying to keep.

But it may be a promise that is destined to be broken.