When Cerberus was brought back to the Gates Of Tartarus by Twilight, it had already been to late. A demon had escaped and has been living in the depths of Everfree Forest ever since. Now, years later, news of a horrible monster that kills almost all travellers that pass through The Everfree Forest, is reaching towns and cities all over Equestria. What is this creature? Why does it kill? And where is it from? Those are the questions Celestia wants to be asnwerred.