Though a thousand questions remained unanswered, Hermione held her tongue for the moment. She drew a deep breath of cold air and solemnly pulled out her wand as she watched the Whomping Willow lazily waving its branches ahead.
Whatever else might be said, she knew how powerful the Whomping Willow was. The fact that it could smash Harry's broom to pieces was enough to demonstrate its threat.
Although she doubted Su Er's claim that the protrusion he had pointed out could quiet the Whomping Willow, Hermione still conjured a little mouse with a Transfiguration Spell and successfully had it touch the knot.
"Nicely done." Su Er clapped and praised Hermione, then stepped into the Whomping Willow's range.
Hermione glanced nervously at the Whomping Willow. Only after confirming that it showed no sign of moving did she hurry after him.
"You should be able to do better than me, shouldn't you? Why did you have me do it?"
"Well... there is a reason. My magic suddenly increased a great deal, and it's become rather difficult to control," Su Er explained. "You know, a Transfiguration Spell requires a steady output of magic. If the magic is unstable, the result explodes..."
Hermione nodded thoughtfully. Looking at the pitch-black hollow behind the knot, she asked another question. "How did you know there was a secret passage here?"
"Dumbledore told me." Su Er naturally passed the buck to Professor Dumbledore. He would still have to give Harry the Marauder's Map later, in keeping with the plot.
After all, it was one of the things Harry's father had left behind. That would count as "returning it to its rightful owner."
"Lumos Maximum!" After climbing into the opening with Hermione, Su Er naturally drew his wand and spoke the incantation for Lumos. He could not use Transfiguration