Liv, Ava, Claire, and Grace try to have one normal sleepover with a new friend named Reagan, but things go sideways when their sleepover is attacked by goblins. The girls find out that the Unicorn Kingdom is a lot bigger than they knew. They discover that someone is trying to steal all the pieces of Neon's horn, and they are pulled into another epic adventure to find out who is trying to restore power to the most dangerous unicorn in the Kingdom and stop it from happening.