Snape had provoked such outrage among the young witches and wizards that, as soon as Professor Lupin finally returned, they began talking over one another to complain.
"It's not fair! He was only a substitute teacher. Why did he give us homework?"
"We don't know what werewolves are-"
"-Two rolls of parchment!"
"And he took points off us for no reason!"
Ron sounded the most aggrieved. He held up both hands, displaying the marks he had deliberately left untreated.
"I spent three whole evenings dealing with horned toads and hedgehog balls! Snape even threatened to make me collect spider venom next time!"
Werewolves? Professor Lupin shook his head slightly. Snape... honestly.
He certainly looked as though he had been ill. His old robes hung even more loosely on him, and the dark circles beneath his eyes made him look sickly.
"Didn't you tell Professor Snape that we hadn't covered that yet?" Lupin asked, frowning slightly.
Everyone began speaking at once again.
"We did, but he said we were too far behind-"
"-He wouldn't listen-"
"He asked us what a werewolf was. Granger knew, but he took points off her!"
"-Two rolls of parchment! Two whole pages!"
They were all brimming with righteous indignation, practically wishing Professor Lupin would draw his wand and challenge Snape to a duel right away.
But Zhang Xiao knew Lupin would never go looking for trouble with Snape, and Snape wouldn't deliberately go looking for trouble with Lupin either.
Of the four Marauders, Lupin was probably the one Snape bore the least hostility toward.
They rubbed each other the wrong way, but that was about it. Had it been James or Sirius, Snape would never have brewed the potion, not even on Dumbledore's orders.
So it was perfectly natural that Professor Lupin merely smiled faintly.
"Don't