the_debt_of_time

"I didn't do it."
"No," Dumbledore agreed. "This Remus Lupin seems to have sent you here," he
said the name with a smile on his lips, and Hermione wondered if the headmaster had
already met the younger version of her friend... or whatever one would call someone who
intentionally tricked a person into time-travelling. As if Dumbledore knew what she was
thinking, he stated questioningly, "A friend of yours from the sound of this letter."
She hesitated. "Yes, sir. At least.. ."
"Do you feel that he lies, that he has sent you back in time with malicious intent?"
"No," she said quickly, no hesitation in her voice. "I trust him with my life." She
remembered the final battle of Hogwarts in the Forbidden Forest. She had trusted Remus
with her life, and he had trusted her with his. She had nearly sacrificed herself for Remus
and Sirius at the hands of Voldemort. She could not help but feel deep pain over what felt
like a great betrayal. "At least, I did until about an hour ago."
The headmaster chuckled. "Or a few decades from now, as the situation appears to
be both."
"I need to go back."
"Mr Lupin's letter says otherwise."
"Sir, I've experimented with time travel before," she said, her voice gaining an edge.
"In my third year, I was provided a Time-Turner in order to have access to multiple classes
without overloading my schedule."
"Forgive me, my dear, but that sounds like the very definition of overloading one's
schedule. Did it work out well for you?"
"It was... fine," she lied as she remembered how frazzled she had been by the end
of the year, snapping at professors and friends, the lack of sleep having practically aged her
an extra few years. "But I've studied Time-Turners since then; I know all the laws and rules
of time travel. Me being here could be catastrophic. I could change things just by talking
to you."
"According to your friend, you being here seems to have already occurred."
She raised a brow. "Sir?"
"I've had a similar thought about time. When using magic to alter the past, are we,
in fact, altering anything, or merely inserting ourselves as the catalyst that causes the future
to happen as it already has?"