Years after their adventures have ended, Spike remains a small dragon, while the other ponies have aged. In order to grow up, Spike must go on his own adventure, but must retain his personality along the way.

Because to let the fire go out, is to let the evil come in.
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This story is set with only up to season 4 in mind. I haven't caught up to the latest seasons for various unimportant reasons, and this disclaimer will let me write without worrying if something I write ends up being contradicted later.