The Spike, The Butterfly Effect
It's just not right that the Spike should've written my favorite stories in not one, but two, fandoms, but there it is. If "Prognosis" was an exploration of the more intimate repercussions of "Hourglass," "Butterfly Effect" is her riff on the epic nature of the end of the episode. A simple, chilling premise explodes into a tale both terrifying and moving. Spike somehow manages to convey an overload of imagery without going over-the-top and provides excellent characterization of all involved, including Jonathan and Martha--rare accomplishments, both. I damn near cried.