Luckily for him, or perhaps unluckily, he realised that the power was in his hands, quite literally. As he stared down at his own tattered book, he huffed and shoved aside his partner's copy, taking the knife without warning and showing him the proper way to do it.
"Look here Lupin, I intend to get top marks for this potion, so just watch. I don't have time for incompetencies." Perhaps he'd been a bit gruffer than strictly necessary, but just being near Remus was making the hairs on the back of his neck stand on end. He gathered up his courage and aimed an impatient look at his partner before quickly snapping his dark gaze back down, finishing up the cutting almost as fast as he could wave his wand. It helped having a lot of practise.
"There, now just use this text and you won't blow the entire cauldron up." He left his textbook propped up on the table, with all of its annotations crammed all over the page.