Chapter One:: Guaranteed Worst Lesson Ever

Hermione Granger, along with the rest of her classmates, knew you didn't have to be a genius like Albus Dumbledore to know that something was amiss. As soon as she entered the classroom for Defence Against the Dark Arts, she had to drink a white potion (which was given by a beaming Slughorn). The potion wasn't horrid but it wasn't pleasant either – she just experienced a deep chill.

Normally, Hogwarts students would whine and moan until they had their confusions answered but as it was Snape who was standing at the front of the room (peering at them with great dislike, if Hermione must add), no-one breathed a word.

When the last student (Neville Longbottom) sat down, a parchment appeared in front of them. As most of the students were looking at Snape (or Slughorn who was also in the room) blankly, Snape sneered, "Read!"

Frowning with confusion and curiosity, Hermione grabbed the parchment in the hopes it would answer the peculiar set-up for today's Defence lesson. She recognised Snape's spidery yet neat handwriting.

A Note to Students

You will clearly have noticed that today's usual Potions class is different as it is combined with Defence Against the Dark Arts. This special class is to enhance your stills at cunningness, stealth, exposure and manipulation (all which are required for Defence Against Dark Arts). As Potions are used for today's purposes, Slughorn has undoubtedly given up his time to prepare the required Potions and also by giving up his Potions class time.

After finishing reading this letter, a cup of potion will appear at your desk. There will be a label on your cup with another student's name who is present in today's lesson. Your cup contains Polyjuice Potion, which will transform you into the student indicated on your label.

When I say so, you are to drink your cup without hesitation and to enter the curtains behind me for transformation. Slughorn and I will Transfigure your clothes to fit and suit you (you don't want to wear a skirt, if you're a boy do you?) During this process, you will be blinded (due to another ingredient in your Potion) and house-elves will take your hand and guide you back into the classroom.

Once everyone's returned, assessment shall begin.

Your job is to conceal your identity and to determine who the other students are. For instance, if you are Malfoy and was unfortunate enough to get Potter, you should act like the charming Potter so others would not guess that it's actually Malfoy.

The potion you drank as you entered the classroom will give you a severe case of a Muggle illness (chickenpox) if you attempt to cheat by looking at the adjacent cup, belonging to the student next to you. Furthermore, you would not participate in today's lesson and have three week of detentions for disobeying orders.

This 'Interrogation and Concealment' (when you're in disguise and trying to identify others) session will run for two and a half hours, where the remaining time is to discuss what occurred and any difficulties obtained. Remember, if you have trouble in today's class, you will be similar to a Squib as interactions with the Dark Arts is more complex.

Points and Deductions are as Follows:
- No-one correctly identifies you at the end of the 'Interrogation and Concealment' session: Credit Points for Defence Against the Dark Arts
- If you correctly identify 7 or more students: Credit Points for Defence Against the Dark Arts
- If you correctly identify 5 students: Do not have to complete the upcoming essay for Potions
- Each correct identity: 10 points for your house
- Three incorrect identities: Penalty of writing a 1000-word essay discussing Witches and Wizards who have failed in disguises
- Five incorrect identities: Must attend Remedial Class for Defence Against the Dark Arts for a week
-No attempt in fear of deductions: Detention for two weeks

Please see either Slughorn or myself to confirm your guesses. We will confirm with a shake of our head to indicate yes or no.

Furthermore, you may think I am too strict with the rules but this class – like all classes – are to be taken seriously and within two years, you will be facing challenges that are more dangerous and difficult than today's lesson. You may believe this task is as easy as muttering 'Lumos' but believe me when I say, you'll be in for a surprise.

-Severus Snape

As soon as Hermione finished her letter and before she had time to get her head around this unusual class, the parchment disintegrated and a cup landed at where the parchment was.

Hermione almost hurled when she saw the person she was suppose to transform into. Draco Malfoy.