Lupin crossed to the door and closed it behind Harry.
“No. Professor Dumbledore managed to convince Fudge that I was trying to save your lives.” He sighed. “That was the final straw for Severus. I think the loss of the Order of Merlin hit him hard. So he—er—accidentally let slip that I am a werewolf this morning at breakfast.”
“You’re not leaving just because of that!” said Harry.
Lupin smiled wryly.
“This time tomorrow, the owls will start arriving from parents… They will not want a werewolf teaching their children, Harry. And after last night, I see their point. I could have bitten any of you… That must never happen again.”
“You’re the best Defense Against the Dark Arts teacher we’ve ever had!” said Harry. “Don’t go!”
Lupin shook his head and didn’t speak. He carried on emptying his drawers. Then, while Harry was trying to think of a good argument to make him stay, Lupin said, “From what the headmaster told me this morning, you saved a lot of lives last night, Harry. If I’m proud of anything I’ve done this year, it’s how much you’ve learned… Tell me about your Patronus.”
“How d’you know about that?” said Harry, distracted.
“What else could have driven the Dementors back?”
Harry told Lupin what had happened. When he’d finished, Lupin was smiling again.
“Yes, your father was always a stag when he transformed,” he said. “You guessed right… that’s why we called him Prongs.”
Lupin threw his last few books into his case, closed the desk drawers, and turned to look at Harry.
“Here—I brought this from the Shrieking Shack last night,” he said, handing Harry back the Invisibility Cloak. “And…” He hesitated, then held out the Marauder’s Map too. “I am no longer your teacher, so I don’t feel guilty about giving you back this as well. It’s no use to me, and I daresay you, Ron, and Hermione will find uses for it.”
Harry took the map and grinned.
“You told me Moony, Wormtail, Padfoot, and Prongs would’ve wanted to lure me out of school… you said they’d have thought it was funny.”
“And so we would have,” said Lupin, now reaching down to close his case. “I have no hesitation in saying that James would have been highly disappointed if his son had never found any of the secret passages out of the castle.”
There was a knock on the door. Harry hastily stuffed the Marauder’s Map and the Invisibility Cloak into his pocket.
It was Professor Dumbledore. He didn’t look surprised to see Harry there.