As Louise searched for something to throw at the Whomping Willow, her foot came in contact with something hard and it took all she had to not lose her balance. "What in Merlin's....?" She blinked and stared down at an upturned cauldron. How had she not noticed that before when she was walking up? Crouching down, she turned the cauldron upright when she pulled out the note and read it.

Passage beneath the tree. Which meant the knot was not a fallacy. But she needed to freeze the tree, or just make herself super fast to bolt for the tree trunk to have time push the knot before it violently took her out. As she was pondering what to do next, there was a breeze that sent shivers through her body and one of the icicles broke off. Bending down to pick up the broken phial, she frowned. Belladonna. They weren't icicles, but potion ingredients? Which meant she needed to brew a potion. Hopefully one that didn't require belladonna. A calming draught would be good about now, though she wasn't sure how beneficial that would be to getting her way to the passage beneath the tree. A wit-sharpening or concentration concoction might work, because while she was intelligent, she was not a Horned Serpent intelligent the way Kyle was.

So what was she meant to brew then? Definitely something, because why would she have been given a cauldron. Perhaps a girding potion would be useful for its stamina and endurance in guiding her to completion of another challenge. And they weren't too difficult to brew, if memory served her correct.

"Accio Potions textbook," she flicked her wand in the direction of the beetle, feeling confident that it would be enough to get her her book, which would provide her with guidance to make sure she didn't forget something.

Squinting up at the phials, she found one of dragonfly thoraxes and flying seahorses and doxy eggs. She needed fairy wings. Breaking off each of the icicle phials, by summoning them with her wand, she then summoned fairy wings and sure enough, there was a phial for that too. With each of the ingredients in her possession now, she set to work. Cleaning the cauldron first, and then "Aguamenti," water streaming from her wand.

Adding the fairy wings, she added some heat under the cauldron too and watched... taking the empty phial from the fairy wings, she counted out ten of the dragonfly thoraxes and then forty of the other, with the extra, Louise merely set the extra to the side. The forty she shoved back into the original container and hovered by the heat under her cauldron to toast them a bit.

Her potion was turquoise, which meant, time to add one measure of doxy eggs and continue heating. And sure enough, there it was, turning pink, a shade she appreciated for just a moment before realizing she would never finish if she didn't keep her focus. Which meant time to add some of the toasted dragonfly thoraxes. She sprinkled a few in, gently tapping the phial to allow them out, the potion growing darker until it was red. Continue heating. And then it turned blue. So many color changes here with this potion, which made her question why she chose this potion to brew, except that it would maybe prove more useful. Unless it wasn't for her, but why give her the workstation and the cauldron?

Adding the remaining dragonfly thoraxes, the potion almost immediately turned silver. At least until she heated it again, when it turned red again. Adding the the remaining three measures of doxy eggs and then the ten untoasted dragonfly thoraxes, she continued heating until the potion turned blue again.

And now time for those flying seahorses, which was the final step, assuming it turned green. And sure enough, after a few moments, it turned green. Taking one of her empty phials, she scourgified it and then swiftly filled the phial. Okay. Now what, was she meant to take her potion and then make a run towards the trunk to open the passageway? Or was the potion meant for something within the secret passageway?