Alex Addleston and Alex Addleston do everything together. They chase Flatt Mountain fireflies. They code secret messages. They collect crawdads named Mr. and Mrs. Sassafras Jorgensen. But when Alex's parents move her family to Kenya, the two friends lose contact with each other.

Half a world apart, each Alex still keeps the other close while climbing trees, counting stars, and playing games. One day, just maybe, they will rediscover what it means to be best friends, no matter what.