“I neither like nor dislike Severus,” said Lupin. “No, Harry, I am speaking the truth,” he added, as Harry pulled a skeptical expression. “We shall never be bosom friends, perhaps; after all that happened between James and Sirius and Severus, there is too much bitterness there. But I do not forget that during the year I taught at Hogwarts, Severus made the Wolfsbane Potion for me every month, made it perfectly, so that I did not have to suffer as I usually do at the full moon.”
“But he ‘accidentally’ let it slip that you’re a werewolf, so you had to leave!” said Harry angrily.
Lupin shrugged. “The news would have leaked out anyway. We both know he wanted my job, but he could have wreaked much worse damage on me by tampering with the potion. He kept me healthy. I must be grateful.”
“Maybe he didn’t dare mess with the potion with Dumbledore watching him!” said Harry.
“You are determined to hate him, Harry,” said Lupin with a faint smile. “And I understand; with James as your father, with Sirius as your godfather, you have inherited an old prejudice. By all means tell Dumbledore what you have told Arthur and me, but do not expect him to share your view of the matter; do not even expect him to be surprised by what you tell him. It might have been on Dumbledore’s orders that Severus questioned Draco.”
…and now you’ve torn it quite apart I’ll thank you to give back my heart!