School’s out, so Phoebe and her unicorn best friend, Marigold Heavenly Nostrils, have the entire summer to play games, visit the pool, and even go camping. Unicorn horns are excellent utensils for roasting things over the campfire, too, even if Marigold prefers toasted apples to s’mores. While exploring in the woods, Phoebe and friends meet a unicorn named Alabaster, who uses a special video game console that’s powered by plants. Throughout her summer adventures, Phoebe learns that being cool isn’t all it’s cracked up to be, and that it’s much better to be your true self. It’s all part of the unforgettable experience of .