Magic. Spike has seen it all around him for years and as much as he'd like to deny it, he's fascinated by it all. In fact, he is so fascinated that he wants to take up magic for himself and prove that he is just as capable as any unicorn. At least, he would if he had a horn. However, he isn't going to let something so minor stop him. He just needs to talk to the right ponies and work some "magic" of his own before he's on his way to becoming one of the most powerful creatures Equestria has ever seen.