His deep sigh of frustration didn't surprise Hermione whatsoever. They'd had many disagreements and outright fights over the years about her potions habit. He'd begged her to stop numerous times, shamed her into remembering their son and a number of other ineffective methods. Addiction was not easily conquered or dismissed. When she allowed herself to think of some of her lowest points in her quest for another vial, she was ashamed. Before she was affected herself, she always thought only weak, stupid people allowed themselves to get addicted to substances that were harmful. How very wrong she'd been.