Shawn returned to Hogwarts, but instead of going straight to his dormitory, he headed to the prefects' bathroom for a luxurious soak and applied some topical medicine to his lower back while he was at it.
It kept hurting there. He would have to ask Snape whether he had anything particularly effective for it.
He certainly did not dare go to the Hospital Wing, afraid the loud-voiced Madam Pomfrey might spread some rumor.
Then he closed his eyes and reflected on his night in the Chamber of Secrets.
He had to admit, he had gained quite a lot.
He had obtained several books on Animagus Transformation and human experimentation, acquired a pet basilisk and sent it to investigate the secret passages in the Forbidden Forest, and discovered something suspicious about Salazar's enormous stone statue.
His greatest gain, though, had actually been that brush with "death."
He had seen the legendary Limbo and witnessed the gates leading to the Realm of the Dead.
His understanding of souls and death had deepened.
Such obscure knowledge, touching on the taboos of magic, was peculiar. Sometimes, understanding simply came; otherwise, no amount of effort to comprehend it would do any good.
As a result, even without the system's enhancement, his Killing Curse could now reach level five in power. If he focused on practicing that spell in the future, his progress would be much faster, too.
His understanding of Petrificus Totalus had also improved considerably, allowing him to develop a variant. If he mastered this version to a sufficiently advanced level, unless he personally lifted the curse...
The victim would remain a stone forever. How was that any different from death?
Still, the spell was of limited use. It might prove useful under particular circumstances, but otherwise, a single Killing Curse would be far