Nurse Redheart takes on a personal quest from the Princesses, Celestia and Luna. She must travel to another world in search of something that the Princesses refer to as "Their Heart." Travelling to the other world Nurse Redheart must find a way to blend in with the humans in order to find that which she is searching for. Lyra, who is already there and through her studies has learned much about humans may just be able to help.