It is an interesting fact that the same method of walking used by muggle supermodels to make their hair fan out on the catwalk was used by Severus Snape to make his robes billow behind him. No one would ever venture to voice this concept to the man if they valued their lives, but nevertheless it remains valid. He did it for much the same reason as those twiggy women do, as well: effect. Snape was a huge believer in effect.

He knew that his billowing robes made him look dangerous and impressive, adding to his perceived size much as certain snakes release their hoods to scare off enemies. He also knew that speaking quietly made people listen more carefully for fear of missing something. He knew that black clothing allowed him to blend in the shadows and force his students to always wonder if he was nearby, watching. He even knew that a proud demeanor towards everyone but the dark lord made him seem as if he was only subservient to him, as opposed to generally weak, and got him less time under the cruciatus.

But the effects of a simple smile were well beyond even his grasp. As the feast ended Snape's mind whirled as he stood from his place, quickly disassembling and reassembling his plans to account for this newest development. A Potter in Slytherin - whoever would have guessed? Obviously, the centuries-old hat was going senile...or perhaps it had spent too much time around the perpetually nutty headmaster? No matter. This just added another layer to his already sweet revenge. At this rate, James would not just be rolling in his grave, but thrashing.

Coming to the stretch of dungeon wall that hid the Slytherin common room, Snape snapped out the password, ex malo bonum, and entered.

"I am sure Deputy Headmistress McGonagall has already explained to you all that your house is ‘like your family' here at Hogwarts," he said with a slight sneer. Silence immediately spread through the bustling common room as the new house members looked at him in fear and the older house members looked at him with the same as well as a healthy amount of respect. He watched the Potter child particularly carefully out of the corner of his dark eyes. The boy's eyes were wide. His sneer increased slightly. "As nauseatingly maudlin as the sentiment is, it is nonetheless true. And as some of those of you from more respectable families will know, loyalty to ones family is paramount." Snape gave a nod to the heirs of the families with purest blood, knowing better than to lose his cover even years after the last sighting of the Dark Lord.

"As such, I expect to see you Slytherins put up a united front when out in the school proper. While in here you are, of course, allowed your disagreements...though I expect you all to refrain from doing anything as common as brawling when in your common room and dormitories. Outside this dungeon, however, you are to show no signs of discord. And above all, if one of you is attacked by a member of the opposite house, I expect that all members of this house to rally against the attacker. There is strength in numbers." He saw a dishevelled black head nodding fervently in his peripheral vision. "Gryffindors will likely harp on this being an unfair fight. Being in Slytherin is being on the losing end of an unfair fight. The school is against you: right up to the headmaster, for all his talk of school unity. Your punishments will likely be harsher than other students from all teachers, with the exception of Professor McGonagall who, while she is more lenient on her students (especially when it comes to Quidditch) will at least not punish you harshly.

"I will, to make up for this, favour Slytherin heavily when others can see. Do NOT think you will escape detention with me, though, at a later date. Other houses will not be aware of your punishment, and house points will not be affected, but you will know the consequences of misbehaving, believe you me."

Snape sent his most baleful glare around the new students and the students who had given him the most trouble in the past, making sure this sank in. The Potter boy was vaguely pale. That's right, boy. You will be disciplined. You will understand cause and effect when I'm done with you. "You are all expected to keep up with your studies. Those who struggle with classes will be assigned a tutor from an upper year. I also expect a certain level of personal comportment and cleanliness. You are to act with respect in regards to your professors and you are to present yourself well in dress and hygiene. Remember, how you look and act is a reflection on Slytherin house and on me." The brat was shuffling his feet now...probably showered once a month, the cretin.

"Maps of the school are impossible to create, given the Unplottable charms on the school*. However, a seventh year will escort you to each of your classes the first week, after which you are expected to find them yourselves. Tardiness due to ‘being lost' will not be tolerated. If you have any troubles, you are expected to first speak to your prefects..." he nodded to the six students in question who rose their hands obligingly. "...and if the situation is direly serious you may talk to me at anytime. My office is down the hall, behind the painting of two snakes intertwined. A brief knock to the door will alert me during office hours and will also trigger an alarm in my private rooms at other times. If you interrupt me at these times without good reason I will be displeased. However, while you are here, I act in loco parentis...as such, I am responsible for your welfare. I do not want you to hesitate to find me if you do have good reason.

"Now, it's been a long night, and you all have class in the morning which you will NOT be late to. So everyone is to go straight to bed right now. First years, the fifth year prefects will now show you to your dorms. Good night."

And Severus Snape left.

As a fan of effects, Snape was also interested in the causes that create them. So it's hard to believe that he did not delve into the possible causes of all the strange reactions Potter had during his speech, or his actions in the dormitory that night. Or maybe not.

Cause, his entire focus was on his revenge on James.

Effect, he saw not Harry Potter, but James Potter's son, object of his revenge.

And so, Harry Potter went off to his new dorm.

Not twenty minutes later, he had a detention. Because he'd punched Draco Malfoy. Because he thought Malfoy would hit him. Because Malfoy approached him in a threatening manner. Because Potter had insulted his family. Because Potter was embarrassed. Because Malfoy'd made fun of his ratty bedclothes. Because they were all Potter had. Because the Dursleys did not provide their nephew with proper clothes.

Cause. Effect.

Too bad Snape could, for now, only see the effects.