Walking through the misty Florida woods one morning, twelve-year-old Rob Horton is stunned to encounter a tiger—a real-life, very large tiger—pacing back and forth in a cage.

What's more, on the same extraordinary day, he meets Sistine Bailey, a girl who shows her feelings as readily as Rob hides his.

As they learn to trust each other, and ultimately, to be friends, Rob and Sistine prove that some things—like memories, and heartaches, and tigers—can't be locked up forever.