Iridis - the reformed changeling - is now happy and settled in Ponyville. However when a strange impenetrable nightmare alerts Luna's attention she finds a deeply damaged and troubled pony in need to help. As a being that senses emotions and dreams she takes on Iridis as her pupil and helps him hone his abiliites. Travelling into ponies' dreams he explores the humorous, the surreal and the inappropriately sexual in a journey that neither of the two will forget. Meanwhile a malevolent nighmare takes form and soon everypony finds themselves in grave danger.