They glared at each other, but Hermione was determined not to be the first to break. She saw the shift, how his eyes softened first, followed by his mouth then the tension lines on his forehead. He broke their staring contest to look down at their cauldron, fiddling with the flame below it even though it was already at the correct temperature. "Sorry," he muttered, not meeting her eye. "You're right, you aren't an idiot. I'm just not used to working with anyone else."