Neon is a unicorn - but she doesn't know it! Unicorns live in the Uni-verse: a secret, parallel world that exists alongside ours. They are the most magical and powerful beings on the planet - but aside from their hidden stripe of neon hair, unicorns look just like you and me. The idea that they are horses with glittering horns is a big ruse, designed to distract humans from the real unicorns. Neon thinks she's just an ordinary girl ... until she receives a battered old lipstick in the post on her eleventh birthday. She's amazed when drawing a line with it across a wall creates a sparkling portal to the Uni-verse. Here, the Unicorn Council badly need Neon's help to defeat the arch villain Scarlet Ditto, who is hell-bent on destroying the unicorns and their world for good. If Ottie can pull off the mission, she'll get to stay in the Uni-verse for ever. But what if she doesn't really want to?