It was eerily quiet and lonely in his rooms. Sep had finished unpacking his things in his new dorms and now he sat on his four-poster bed, staring at the trunk of his counterpart. It was a curious–looking trunk, almost new; as though Harry hadn't used it much. He felt as though he were invading the other's private space as he walked over and opened the trunk, but he knew that he would have to learn about his life in this dimension.
The first thing he saw as he opened the trunk was a photo album laying on top of all the clothes. Its edges were wrinkled and worn, as though the other boy had spent many hours a day looking through the book at its pictures. Turning the first page, Sep was shocked to notice a young woman with fiery red hair next to a man with a messy mop as black as his father's. In their arms lay a small infant.
This could only mean one thing and Sep hoped his assumptions weren't correct.
Dinner so far had been a quiet affair. Sep sat next to his father taking in his surroundings. He, his father and Professor Dumbledore, were not the only ones gracing the Great Hall this evening. So were Professor McGonagall, Trelawny (to whom he had just been introduced) and Sprout. Sep decided that there was no time like the present and brought up that which had been on his mid all day.
"Father," he said, startling the unknowing teachers to no end, "when had Septimus been given to the Potters?" At his words, Professor McGonagall sucked in a deep breath of understanding and his father scowled deeply. No one said anything for so long, that Sep feared he would get no answer. Finally, Dumbledore spoke. "Septimus, one thing you must remember, is that in this dimension, Tom Riddle turned into an evil dark lord who calls himself 'Lord Voldemort'.
"At the time, you and your counterpart were switched, Lord Voldemort terrorized the wizarding world and your father worked as a spy for me between Voldemort and the side of light. At the time, Harry lived with your mother as both had to be hidden from Voldemort. Luckily, when Voldemort discovered Severus' deceit, Harry had been visiting with the Potters, good friends of Patricia's. The Potters had a son, Harry. When they heard of Patricia's death, they knew they must hide her child to keep him safe from Voldemort. So they decided to disguise your counterpart as their son's twin.
"On the eve of Halloween, Voldemort decided to attack the Potters. Only one baby survived, managing to vanquish Voldemort. We were never completely sure which boy had survived that night, but we tended to believe it was Harry Potter, not Septimus Snape. We were wrong."
"But Father, why didn't you take in Septimus when Voldemort had been defeated?"
Severus sighed. "We knew that the Dark Lord had not been completely annihilated. We knew that he would one day return. We had to make sure that the Dark Lord's remaining supporters did not find out that Septimus survived. Besides, I truly thought my son had died, not that of my rival."
Later that day, Sep was walking across the castle grounds toward a large, obscure tree beneath which he sat. This tree stood away from the forbidden forest, but never-the-less seemed a part of it when observed from the castle.
Under his arm, the dark-haired boy carried a thick tomb entitled: Advanced Potions beyond the average education. Sep had always been interested in Potions, even before he had learned of his father's talents, and his dad had encouraged him to broaden his knowledge of the subject.
Sitting down, Sep opened to a marked page and began reading about the Zendonni Formula. This was a highly advanced potion which bordered on being illegal. The purpose of the formula was to transport items from this reality to another. He was quite curious if he would be able to communicate with his counterpart, Septimus, using it. According to the description, he was to put a drop of the Zendonni Formula onto said object and it would immediately disappear. However, he wanted to experiment with Boar's clover to transform a mirror into a porthole of sorts.
First, however, he would have to get the help of his father. His dad had been happy to aid in his experiments, but he had the feeling it would be much more difficult with this Severus Snape.
The next morning, Sep went down to the Great Hall and sighed in disappointment, as he scanned the long breakfast table. It was as though his father had known he would seek him out as he hadn't attended the evening meal yesterday either.
Septimus made sure to sit near the Heasdmaster and let the meal commence for 15 minutes before posing his question. "Headmaster, could you tell me where I can find my father's quarters?"
Dumbledore looked up, surprised. "He did not tell you where you could find him?" Sep shook his head and Dumbledore looked at him sadly. "Your father resides in the dungeons behind the portrait of a snake lazing on a rock before a small hut in the woods. You'll have to knock because, even though you are his son, I will not give out passwords without permission."
Sep sighed and thanked the Headmaster before heading out of the Great Hall and down the only winding staircase into the dungeons. After wandering for about 15 minutes, the teenager finally arrived at the designated portrait.
"Well," he said to the snake, which was lazily watching him. "Here goes nothing." Showing a confidence he did not feel, he knocked on the frame of the portrait. Silence reigned for about five minutes before the portrait opened and a cold voice said: "What do you want?"
"Good morning, Father!" Sep chirped, entering Severus' quarters. If his father was astonished, he did not show it. Instead he watched stoically as his son shifted from one foot to another before him.
Finally, Sep caved in and answered the question. "I have come to request your help. Dad and Uncle Albus always told me how good you were at potions and that I had inherited by ability from you." Severus remained silent, his eyebrow raised in query. "I want to try and make a connection between two dimensions through the use of a mirror and a potion. I have a basic idea of how to do this, but there are certain components that escape me."
"And how did you come to the conclusion that I would want you to blow my dungeons up? Despite being my son, I have no doubt that you are as incompetent as the other dunderheads I teach." Severus turned his back and walked towards a door on the other side of the room, making Sep's blood boil till he no longer could hold his tongue.
"Some father you are! No wonder Septimus never found out about his heritage, you don't give a damn! If that's the way you feel, I will leave you be and see you only at meals!" With that, Sep made his way back to the portrait. Before exiting the room, he turned to have the final word: "For your information: In the other universe, it was I that invented Wolfsbane and Veriteserum."