Polyjuice

You are currently in your dorm with two other student, a fellow Hufflepuff named Darrel Tate and your Ravenclaw friend Helena Mallow. The girl is holding a vial of polyjuice, the plan is simple : go into the teacher office and change some grades.

Both you and Helena failed last year, and since the beginning of the year you have been helping each other. Darrel is just here for the support like a good friend.

Helena explained to you that she didn't feel it. The ingredient were not the freshest and the potion color seems off. As good as she is, crafting this potion is hard.

You are not one to be afraid, so you take the vial and down it.