the_debt_of_time

"I imagine I'll be seeing them both next Friday," she said with a stern expression.
"Fighting on the train; honestly. Please see to it that you keep your prefects in line this year,
Miss Evans. I should hope the Head Boy will have no problem attending to his duties as
well with an ounce of maturity."
James offered her a crooked grin. "I'll try, Professor."
"I won't catch the two of you hexing one another in the halls?"
"To be fair," James insisted, "I've never hexed Lily."
"And I've never been caught hexing Potter," Lily admitted smugly.
"All right, off with you both." McGonagall began shooing them toward the exit,
and Mia ducked behind the doors of the Great Hall, watching as they all stepped out.
"There are patrol schedules for the two of you to write up, and I'll be busy ignoring the
rumours of a party happening in Gryffindor Tower. I'm certain neither of you is aware of
such a thing."
"Of course not, Professor," James declared. "If there is a party, you can be certain
that I'll put a firm stop to it. No parties in Gryffindor Tower after midnight."
"Eleven," McGonagall countered after a moment of contemplation.
"Deal."
The professor then turned and addressed Lily. "Miss Evans, can you show the Head
Boy to your new quarters? I assume you're already aware of them since you've been pining
for the position of Head Girl for six years?"
Lily frowned, looking momentarily offended. "I wouldn't call it pining exactly, but
yes, ma'am, I know where our rooms are."
"Then I shall bid you both good night." McGonagall left them by the stairs, turning
back toward the Great Hall where she made eye contact with Mia. Sending a particularly
censuring glare in her direction, Mia bowed her head with a smile and held her hands up
in a "Sirius" gesture of defeat before she side-stepped the professor and walked toward the
stairs.
James and Lily were hovered close together, looking over some parchments in Lily's
hands, unaware of Mia's nearness. Curious—and before they could spot her—Mia
disillusioned herself and silently slipped up behind them.
"Are you going to the party, then?" James asked as he walked with Lily toward the
staircase.