I love it. Yes, yes, yes, R.A.B. in love with a muggleborn, or someone who's not a pureblood at least, he only said her grandmother was a muggle, but he fell in love at last, I'm so happy about this. Maybe he did go after that locket. Gah, how am I to know? I know, I keep reading, and follow this story so I know when you've updated.

I knew it! I knew you shipped this ship! I'm glad. I like this ship, it's fun.

So Sirius's potion that he made the previous summer is definitely going to fix whatever is wrong with him? But he's still having headaches. I thought he couldn't have custody because of whatever it is?
You know what, I bet it's something like Sirius tried at some point to make himself not a Black. He was young and stupid and tried something to make him not the same blood as his family and it backfired and now he has dangerous symptoms or something. That's my guess. I mean, he was researching Blood magic a lot for years, so it's got to be something blood-related.

Well, if Lucius didn't kill Regulus, Kreacher would know, wouldn't he? Gods, I don't know. But this is all really cool.

Aha. So that's how the last bit was connected - this is even better than Harry and Tonks finding it in a bedroom, I love this. So what happened about the Horcrux? Did Regulus even find out about it? Or did he find out and then tell Narcissa and then Lucius killed him for wanting to destroy it? Oooh, or maybe he tried to destroy the diary as well and Lucius killed him for that. But what about the locket, then? I guess we'll just have to find out.

Okay, I kind of knew that was coming from the beginning of the chapter. Why do you have this chapter here, anyway? Is Harry or Nymphadora reading it? Did they go through the rooms upstairs and find Regulus's diary?
By the way, have I ever mentioned how I love your writing? It could just be because I've gotten tireder and that tends to make me gush more, unless I'm so tired that I can't write anything coherent, which does sometimes happen when I'm reading fanfiction, but I think it's more that I love your writing. And I wasn't just thinking that this chapter, either, I was thinking that when I thought of your characterization of Sirius and other characters, when Harry was interacting with Collin or helping Neville, when interesting things happened that made me want to know what happened next so I could understand the mystery because even though I know the canon and several AU's backwards and forwards you can still make a story where I feel the suspense and can't guess everything, and I thought it whenever Harry or Hermione or Ron had a brilliant or sensible thought that we never heard them make in canon. I even thought it when Hermione had the idea to break into Sirius's office - well, I more had the thought of, "That is so typically Hermione!" with a laugh because she does tend to have these crazy ideas of breaking a bunch of school rules just to find out something when she is normally the most sensible and rule-following of the lot.
Anyway, you're awesome, and this version of Regulus is awesome, and I can't wait to read more.

Well, I don't know if Regulus is dead or not, but I think he probably is. In the books he disappeared before Harry's parents died, and he did here too, and the AU'ness probably isn't enough for him to have gone to someone for help with the Horcrux thing, although I suppose it's possible. But that wouldn't be very fun, would it?

Thank you, Brutus Swift. Hermione needs some good appreciation. I'm in love with this chapter, by the way.
Now, the only thing that is missing is for Harry or someone to see Peter's name on the map. Except he's not going to sneak out anymore, so he probably won't be using it - I don't know. But Sirius starting to doubt Remus's guilt - I'm so incredibly happy right now.

Aha! There is still a chance Harry could go live with Sirius. And so he'll still have at least one thought strong enough to form his Patronus.

Well, that's one way to do it. Just spit it out, no warning, no waffling about how to phrase it, just interrupt him and say it. You know, I think I like it this way. At least he's not saying it while he's still angry.

Well, at least Dobby isn't trying to restrain him using questionable means.
Maybe Sirius's illness has to do with his mood changing. And headaches. Oh no, what if he has cancer or something? No, he wouldn't look this good after twelve plus years with it, esp. if it was in his head, and besides that's a muggle disease. So, something that causes headaches and gives him temper problems.

Well, tell him some of the things that you know, and maybe some of the things that you suspect, and see what he makes of it. It's really not that hard, Harry.
Except that it is, and Harry's a young teenager and everything is difficult at that age, especially interacting with people.

Riiiight. Harry, staying out of trouble. What was he doing Christmas night, again?

A button. Is this recent? Is Regulus alive? Or has the button been there for years and they just mentioned it now? Probably recent, but I don't know...

Oh, damn. Well, at least Snape will probably not be paying attention to Neville in class for a while. So, Sirius is ill with something. That explains some, but not all of the questions.