calculate precisely which lives he cannot save and how to remain impassive when he must, a self-control he needs when witnessing the death of Charity Burbage. At all other times, he has been protecting others, feeling connected to them, increasing the potency of his magic with every life saved. This change in him shows the importance of Snape and Harry disliking each other to the end. They may come to respect and understand each other, but neither feels affection, nor is that a requirement.
