This has to be the most stunning representation of not only Severus Snape but also his relationship with Lily and the Slytherin hierarchy. I have been reading this story for the past six hours, and will most likely find time to do so again in the future.
Author's Response: Six hours? Wow. I'm glad this story aged well, since so much of it was based on the guesses and hints available in HBP. Thanks for the review!