Arithmancy was Hermione's favorite subject, and for good reason. It functioned off of logic, not feelings or 'auras,' and most of all would work whether or not she had someone to bounce her ideas off of. From an academic perspective, it was fantastically satisfying. But most of all, it had almost foolproof answers to any problem you could pose to it.

The variables were like math, or science; you created stable elements of the equation and balanced them with the unknown variable. Through tweaking one known variable at a time, it was possible to figure out the statistical likelihood of the unknown variable.

She had worked on this at the beginning of the summer, balancing Sirius's convict status, his emotional attachment to Harry, his hatred of Pettigrew, and his self-preservation against his odds of survival and location. She used the South America model as a control, because that's where Sirius went in the original timeline. He had a 99.9% chance of survival in South America – as close to 100% as you could get, when playing with the future – but she knew he'd never been happy there.

So she had to run the numbers, and figured out that his odds in Britain (45%) and France (53%) were just too low for comfort. Germany, on the other hand, was at a happy 89%, and she found if she sent him to eastern Berlin, and nowhere else, that percentage raised to 99%.

In the resistance, she and Septima had run countless equations just like this one, although they were often more convoluted and took up much more parchment. Arithmancy, thankfully, counted as passive magic, so Hermione could complete the equations during her research days. She still did much of the cooking and cleaning in the house, which she knew made her parents happy. She had been hoping to get their help with the whole Harry situation, maybe moving him out of the Dursley's care legally or at least taking him in for part of the summer, but her arithmancy equations were frustratingly low (22%).

This equation was a tougher one: Harry was at the center of many variables she counted as facts, since they had really already happened. This meant that she had to measure the likelihood that an event would go well, and that the circumstances would stay the same for long enough. After triple-checking the three pages of messy notes, she confirmed that her calculations were right: Harry had to stay at the Dursleys for at least six weeks this summer, or he wouldn't survive Voldemort's resurrection.

Afterwards, he was safe to go wherever he chose for the summer, but that decision would cause its own ripple effects. She loved Harry like a brother, and truly loathed the idea that he was stuck at the Dursley's for so long, but she had to trust the equations. Plus, there was only one more week (non-Hermione time) between now and then. She wanted to help him live with Sirius before the Quiddich World Cup, and so she started yet another arithmancy equation.

Sirius was living in Berlin, meaning she would have to coordinate Harry traveling from the Dursley's to Berlin and then back again before the Weasley's picked him up for the Cup. Hermione was hesitant to let the Weasley's know that Harry was living with Sirius – they were quite close to Dumbledore, and she was certain Dumbledore would have strong opinions about where Harry should go.

Dumbledore definitely had his heart in the right place, but he simply didn't know what the future held. She didn't know how he would react, and so she avoided the whole issue. What he didn't know wouldn't hurt him.

Plus, she wasn't convinced he didn't want Harry to stay at the Dursley's out of some messed up psychological theory; Hermione had a different idea. Firstly, Dumbledore didn't know enough about Harry's home life to judge whether or not he should be rescued – as far as she knew, Harry was incredibly tight-lipped. She had only gotten the full extent of the Dursley's abusive behavior after many drinks, and that was a year after he last lived with them.

No, Hermione wanted Harry to be trained. He always had the potential for greatness, but unfortunately Ron's lackluster approach to schooling made Harry slack a bit too much to be a serious threat. And she couldn't do it herself; the last thing Harry knew was her running away from a boggart in her Defence Against the Dark Arts final. She simply didn't have the credibility.

Sirius was the perfect choice, then. Not only did he live in Germany (where the underage magic law was even lower – fourteen!) but she also knew how much Harry loved Sirius and visa versa. They never had a chance to really get to know one another, and Harry deserved someone who would be a parental figure. And Sirius would treat him like Just Harry, the person he always wanted to be. Not the Boy-Who-Lived, not the Chosen One, but a kid who needed a little more love in his life.

Hermione shook herself away from her musings – she needed to act. She had done quite enough thinking already. Just then, the mirror buzzed. Sirius was calling.

She picked up the mirror, "Hey Sirius, how are you doing?"

"Hermione! I don't know what you did, but Kreacher is amazingly better than before. I can't believe it! He actually made me lunch without trying to poison me today, and I didn't even ask for it."

"That's brilliant! I'm glad I could talk some sense into him." She smiled. "By the way, I was wondering how you'd feel about having Harry stay with you. He really hates his aunt and uncle, and now that you've got a place…"

"Bloody hell, yeah I'd have him!" He said happily. "I wasn't sure whether I'd be able to, you know, after the rat escaped." He ran a hand through his long hair. "Do you really think he'd want to stay with me? I mean, he barely knows me."

Hermione reassured him, "trust me, Sirius. Even if he didn't like having you as a godfather, he would do absolutely anything to get away from the Dursleys."

"You're a great friend to him, Hermione. And to me."

"I know he would do the same for me." She said simply. "Although I do have one request," she hedged, waiting to see his reaction.

"You've helped me out plenty, Hermione. What do you need?"

"Could you teach Harry some Defense? He's always getting himself into trouble. And I swear Professor Snape can read minds…" she said, which started a whole new slew of questions.

"Snape? You mean Severus Snape? The sniveling, slimy snake that always followed Harry's mum around?"

"I assume the same. He's the head of Slytherin, and the Potions Professor. He seems to really hate Harry for some reason."

Sirius was fuming. "Oh I'll teach Harry how to deal with the git. I can't believe they ever let him be a professor, he was a right tosser."

Hermione pursed her lips, but didn't say anything. From what she'd heard, Sirius was a right tosser at Hogwarts. She didn't need Sirius knowing she thought so, however, so she continued, "I can ask Dobby to take him to you – Dobby loves Harry. I'll give him a few days to pack and all, but I know he'll be pleased to see you."

AN: Happy mothers day, to all the moms out there! And a thank you to everyone who reviewed. I know I'm falling behind on responding to reviews; I'm so wowed by the response! I'll get around to replying, I promise. A lot of people have been giving me suggestions on what to do next: you're welcome to suggest/guess what will happen, but I've got a pretty solid plan for at least the rest of the summer - there's a lot of exciting stuff coming up! Look forward to some Slytherins entering the game.

As a response to guest commenters, MiRug and Ania: thanks for your support! I'd be happy to respond to you and discuss your theories, but I don't want to distract from the story - if you're logged in, I'll definitely try to reply to your comment.