Chapter One: Prologue
The order of the Phoenix, the 'elite of the light', hadn't been the same since Voldemort kidnapped Harry. It had happened just after Christmas in his 5th year, and was a terrible blow to everyone, but to Hermione, Ron, Remus and Sirius especially. Shortly after Harry's disappearance, they themselves had gone missing, blinded by grief. The order presumed all of them dead, as they had not heard from them in the 18 months since the kidnapping. A rescue mission gone wrong, they said.
But none of this was true. All of them were quite alive, and more powerful than anyone could have imagined. And they wanted revenge, not only on Voldemort and his Munchies.
Oh No
Why leave the roasted flamingos out as well?
Harry, once kidnapped by Voldemort, was subjected to horrifying torture. Bellatrix, Lucius, and Dolohov were rather good at it. In total, Harry was there for a week, yet that week changed him.
He'd gone insane.
Luckily for Harry, he was strong enough mentally that he remained lucid enough so that you could understand him most of the time, but he could easily lapse.
When Ron, Hermione, Remus, Sirius, and Surprisingly enough Snape (the order thought him dead too. Killed by Voldemort for being a traitor) managed to bust Harry out, they were horrified at what had been done to him. For months they'd tried to pull him out of it, but to no avail. They just began to accept it as part of Harry, and helped him when it got really bad. They were the only people Harry felt safe around, especially Sirius.
Sirius had felt dreadfully guilty about the kidnapping, claiming that he should have protected Harry. To try and work through this, he spent more time with Harry than anyone, and, slowly, the two fell in love. Harry was sane enough that he could usually function normally enough, and this included love. The relationship and deep-seated emotion between them helped Harry remain lucid.