Disclaimer: J.K. Rowling owns the characters mentioned in this story as well as the locations.
The Ultimate Secret
For years he had planned and now it was approaching the "witching hour". He smirked when he thought of that muggle phrase. It started with deceit and ended with planning. Planning took more time and skill than most witches and wizards were willing to put forth. He, however, had all the time in the world to plan, to plot and to scheme. It began with the death of his beloved Lily, the woman he had given his heart to and been rejected by when he had spoken that stupid word. The promise he made to Dumbledore for the protection of her son had made him a spy. But that wasn't the secret. Everyone knew that part now thanks to the playing out of the plans of the ultimate puppeteer. He had free agency and had not only been a double agent, but had worked out an end game that would suit himself and nobody else. He started small and worked his way up to where he was now.
In the beginning he had his teaching salary deposited into Gringotts Wizard Bank, but when he formulated his plan he needed a fall-back solution. The muggle world provided the secrecy and escape that he would need to succeed. He began researching in the field of microbiology and nanotechnology quietly on the side. He enrolled in the University of Edinburgh's College of Medicine & Vet Medicine (MVM). This was done through a series of forgeries, curses and generally serendipity.
He had a muggle birth certificate because his father, being a muggle, has insisted that his mother Eileen Prince Snape give birth in a muggle hospital. The next step required taking the original birth certificate to the courts after it had been proven that his father had beaten his mother to death and requesting a name change. The courts finding sufficient reason changed his name in the muggle world to Sebastian Prince, no middle name or initial thank you. With this he was able to open bank accounts, obtain a British Passport and a driver's license. He was able to legally change the primary school records with his new birth certificate, but had to find a legitimate public school large enough that he would not stand out as anything other than another student. Once he had decided on St. Edward's School, Oxford he had to perform the confundo charm on a records clerk to add his name and award him sufficient A-levels to allow him easy entry into MVM. To cover his tracks he wrote letters to certain instructors that "reminded" them that they would recommend him when he was ready to apply to University. Once he was truly enrolled in University he was able to take classes with the aid of a time turner that he had "borrowed" from Professor McGonagall and he graduated with his advanced degree in before she had need of it in 1993 for Hermione Granger.
The school achievements in the muggle world were his biggest pleasure to date and his biggest secret, but they were but a step toward independence. He did research for the muggle world while he was creating the potions for the wizard one. He wrote academic articles and works on his muggle research as well as the wizarding. All money he earned from his muggle ventures went into muggle investments and banks. All earned in the wizard world went into Gringotts. Living in his parent's home in Spinner's End and Hogwarts allowed him to accumulate a decent fortune in the wizard world and amass a fortune in the muggle. When he built his house in the wilds of the Highlands he made it unplotable and from time to time would daydream of the day he would be allowed to inhabit it as a free man.
When Voldemort came back and used the snake, Nagini, against Arthur Weasley, he knew what he must do. He began preparing for his demise. He didn't know that this was the method that would be used to kill him, but it was certainly one of the Dark Lord's favorite methods of killing. Using the knowledge of the type of snake venom he would need to build "immunity" or at least a tolerance to in order to allow time for an anti-venom to work was the first priority. Second was to work on shielding charms that would work much like the body armor muggles wore for protection against bullets. Because spells and jinxes could be performed anywhere on the body, he would have to figure out how to embed the protection over the skin or make it repel or heal after attack.
This was the day Severus Snape knew he was going to die. The knowledge of Potter's return to Hogwarts had been shared with him by the Headmasters in his office. This was the penultimate challenge to Voldemort. Voldemort needed to stop Potter from destroying the diadem lest he could be destroyed. Voldemort needed to kill Potter and the fact that the elder wand was not working meant one thing. The Dark Lord was aware of the legend of the elder wand and he knew that Snape had been the one to kill Dumbledore, the last KNOWN owner of the wand. Severus being even more knowledgeable about the wand knew that he was not the wizard to whom it answered. He and Harry Potter both were aware of the fact that Draco had been the owner of the wand due to unarming before Dumbledore's death.
Severus prepared to meet his demise. He took the shielding potion and put a vial of anti-venom in the pocket of his robes. As an extra precaution he strapped his wand tightly to the inside of his left boot with a blood seal so that he would be the only person that could remove it. He carried a second wand that he had found in a file drawer of confiscated contraband in Filch's office. He waited for the summons in his old quarters in the dungeons of Hogwarts that he had not relinquished when being named Headmaster. (Slughorn thought them too dreary, so that was easy.)
Lucius Malfoy rapped on the door and told him that their master wanted Severus to join him in the Shrieking Shack. Immediately he set off to meet his destiny while Malfoy Senior slunk back into the dark halls of the dungeons. When Severus arrived he was right. There was the snake and the Dark Lord. Voldemort disarmed Severus easily tossing the wand aside. Then he commanded Nagini to kill. Voldemort's departure from the shack was closely followed by the arrival of Potter, et al. The pain of the bite was excruciating, but he kept his head and told Potter to take the memories he had compartmentalized for sharing. When the trio left the shack, he slipped the vial from his pocket and drank the potion. At least he didn't have to cut himself to get past the blood ward to access the wand in his boot due to the blood on his arm from the snake bite. Severus Snape disappeared from the Shrieking Shack and the gossip had it that the Death Eaters had stolen his body and burned down the shack when they were made aware of his questionable allegiance to their master.
Two days later a tall black-haired man with a hooked nose dressed in motorcycle leathers and pushing a Honda motorcycle similar to the one that had won the 1997 British Motorcycle Grand Prix. He was not a handsome man, but he was striking and looked sexy and dangerous at the same time. He rode off into the sunset and Sebastian Prince took up his place in muggle society as a reclusive scientist.
Hogwarts School Arithmancy Assignment #2
Task: I would like you to write about a secret. This could be a secret shared between friends, a child hiding a secret from their parents or even a secret room or place. Be as creative as you like.
Optional Prompts: Daydream, heart, handsome and gossip.
Word Count: 600 min, 2000 max