The experiment to cultivate Snape's cells was going remarkably well.
Wizard cells were astonishingly more robust than those of ordinary mammals.
Jon had been concerned that the tiny sample he collected might not grow well in the culture flasks, or that it would take too long. But he'd clearly overthought it… In just over a dozen hours, Snape's cells had filled the entire flask.
Next, Jon carefully digested and passaged the cells...
For the next week, he checked on them daily.
Due to the limited conditions, he couldn't clone a full piece of Snape's epithelial tissue in such a crude environment, so he simply allowed the epithelial cells to multiply rapidly and continued culturing them across generations.
Of course, he still made sure to return to the Hufflepuff common room before dark each day.
Even though he knew the Basilisk wouldn't appear during this time, it never hurt to be cautious.
By the end of the week, the once-minimal sample had expanded into over a dozen flasks full of cells.
...
On the second Friday of February, Jon decided the cell quantity was finally sufficient.
He carefully collected the contents of more than ten flasks, digested and centrifuged them, and combined the results. Naturally, he saved two flasks for ongoing cultivation, just in case.
Looking at the white clumps, each about the size of a pinky nail, he wrinkled his nose—they didn't look pleasant, but they were, undeniably, once part of Snape's body.
He hoped this would work.
With everything prepared, Jon took a portion of the cell paste and added it to a cup of Polyjuice Potion he'd brewed earlier.
The potion immediately started hissing and bubbling… Within a minute, it had turned deep red.
Staring at the bubbling red liquid, Jon's nerves began to settle.
Holding his nose, he downed the potion in one gulp. The taste wasn't bad—slightly bitter, but nowhere near as disgusting as he'd feared.
Just like before, his insides started churning violently, like he'd swallowed a handful of wriggling snakes!
Jon doubled over, quickly and expertly pulling on a larger set of robes.
A burning sensation spread rapidly from his stomach to every part of his body. It felt like his body was liquefying, his skin bubbling like molten wax... He collapsed to the floor, watching his hands grow larger, fingers thickening, nails widening, shoulders stretching—
One minute later, he stood up.
A thin frame. Greasy, limp black hair. Sallow skin. A hooked nose… and eyes cold as ice.
Severus Snape stood in the Room of Requirement.
He had succeeded.
...
Jon did his best to suppress his excitement.
Since he hadn't cultivated enough cells for a lasting transformation, every second now had to count.
Compared to the agent special forces operative he had used before, Snape's body was far weaker—he looked downright sickly. But for a wizard of Snape's caliber, that hardly mattered.
Jon sat down quickly, closed his eyes... and began trying to sense the instinct Snape used to shut his mind.
"Focus. Close your mind…"
"Restrain your thoughts…"
"Don't think. Don't remember. Don't feel…"
Ten minutes later, Jon opened his eyes again.
Just as he expected, this method was incredibly effective. Tapping into Snape's instincts and understanding how he practiced Occlumency had already taught him more in ten minutes than three months of solitary study ever had.
Jon closed his eyes again and continued.
The human mind isn't a book—its contents aren't laid bare for anyone to read. Thoughts aren't etched into your skull for others to see. Legilimency wasn't just about reading memories—it was about interpreting contradictions and emotional responses to find truth.
Occlumency, then, had to do the opposite. It required sealing off conflicting memories and feelings, preventing others from forming an accurate picture of your thoughts. Real memories had to be buried deep and hidden beneath lies—so deep that not even the most powerful wizard could uncover them.
...
An hour later, Jon Hart's slightly smaller body reappeared in the Room of Requirement.
He gasped for breath, trying to recover from the painful transformation... But his mind felt sharper than ever. He was closer than he'd ever been to truly mastering Occlumency.
First, a break. Luckily, he'd grabbed a stash of chocolate from the kitchens a few days ago.
Jon bit into a large chunk of chocolate, restoring some strength.
Then he quickly retrieved a second dose of Polyjuice Potion, pre-prepared and hidden in the Room. He added more of Snape's cells and this time drank double the amount.
Transformed into Snape once more, Jon resumed his practice.
...
A few hours later, Jon's face had turned pale.
But the results were undeniable. At one point, he asked the Room of Requirement to fill the space with blaring noise. Yet even as he stood in the middle of the chaos, he remained completely unfazed—calm and focused.
He couldn't completely shield his mind yet, not to the point of full protection from Legilimency—but he could actively bury all his "unpleasant" memories deep beneath layers of false ones, beyond anyone's reach.
...
After eating a few more pieces of chocolate, Jon felt slightly restored. He stood, preparing to return to the Hufflepuff common room.
That's when he realized—there was a problem.
He'd spent over six hours in the Room of Requirement without noticing... It was now past 9 p.m. Greenwich Mean Time, and night had fully fallen.
Curfew had begun long ago at Hogwarts.
Jon pressed his lips together—this could be a bit tricky.
There was little chance the Basilisk would appear at this hour—but he wasn't about to take that risk. And if he got caught by Filch, it wouldn't look good either.
Wandering the halls at night was still a violation of school rules.
After thinking it over, Jon took out a small bottle of mud-colored Polyjuice Potion.
Moments later, agent Pavlov reappeared in the Room of Requirement.
Given Pavlov's skills, evading Filch—should they cross paths—would be trivial. After all, Filch was just a Squib.
A ten-minute dose would be more than enough to get from the eighth floor back to the Hufflepuff common room.
Pavlov donned a large black wizard robe, pulled a cloak over his face, stepped out of the Room of Requirement, and vanished into the shadows of the castle.