"Think of your happiest memory."
Gavin stood beside the lectern, wand in hand, and casually pointed at the empty space ahead as he recited the instructions by rote:
"Make it as specific as possible, focus all your attention on it, then say the incantation."
At half past four in the afternoon, sunlight slanted through the high windows beside the library, illuminating every speck of dust in the air.
They were in the Abandoned Arithmancy Classroom around the corner on the Second Floor.
They had pushed the long tables and high-backed wooden chairs against the walls beforehand, leaving a reasonably spacious patch of flagstones in the center.
Hermione had placed her schoolbag and two thick stacks of parchment on the corner of a table by the window. The Book of Spell lay open in the middle, with a pale pink-and-white slip marking the page on the Patronus Charm.
It was an advanced treatise written by Miranda Goshawk, and the earliest edition had even been kept under lock and key in the school's Restricted Section.
Although Hermione's copy was only the ordinary lending edition, its advanced defensive magic would normally not be covered until sixth or seventh year, in the advanced classes preparing students for their N.E.W.T.s.
After Draco had been taken to the Hospital Wing the previous afternoon, Professor McGonagall had tripled the patrols around the school gates. The two Dementors that had strayed out of bounds by the Black Lake had also been driven back beyond the designated boundary.
As for how the school was negotiating with the Ministry of Magic, Gavin had not asked, and Hermione had not mentioned it.
At Gavin's first words, Hermione's brows immediately knitted together.
"I've already tried all that."
The girl stood in the center of the classroom with her chin slightly raised, her