This was so incredibly HOT and so in character for everyone. I have always thought that Severus and Lucius make a lot of sense as a couple, even as an unwritten background in canon, and this story just made them really alive for me.
I do like Hermione with either Sev, Luc or both as well. The last person on earth she belongs with is Ron and you showed why oh SO well. That scene with Lucius seducing Severus by reciting how he invented a spell fit with Severus' character perfectly. It also felt totally right for Lucius to be that seductive however suited his partner best...
The idea of the Dark Mark as a type of Imperius spell is one I'd not read before and you made it truly believable and frightening - both for the loss of control involved and for Harry's reactions to using it. It felt so real I started wondering if that seductive effect of the power had to do with Riddle going from slightly bad, to horrible to Dark Lord with glowing red eyes...
Excellent fic, wonderfully wrought. Definitely one I will put in memories and read again.