oh, i adore this. i don't often read post-azkaban r/s because there's so much hurt and confusion between them [necessarily so, i think] but here the mix between au and canon makes the distance between them bearable. also, finally a good reason for why remus would marry tonks! and of course also for why he'd leave her. needless to say, i imagine remus and sirius to emerge from the battle at hogwarts unscathed and happily ever after :).