One late night in early June, Will completed the final step in the Room of Requirement. It was the happiest he had felt in months.
A complex silver magical structure floated before him. Countless fine threads of light wove together into a three-dimensional pattern, like a miniature galaxy or the heart of some creature, slowly beating. Near it, Will could sense a faint joy.
This was the Joy Core.
After months of research, experimentation, and adjustments, Will had finally built this core of Ancient Magic.
It stored no specific happy memories. Instead, it held the conceptual structure of joy itself. When activated, it could draw fragments of joy from its surroundings and convert them into usable magical energy.
The Joy Core had another application, too: it could plant joy in a person's emotions, then remotely harvest the joy that overflowed from them.
That was how Santa Claus's gifts worked. For years, he had kept giving presents and spreading joy, until the amount of joy he had collected had grown almost beyond belief.
And Will thought it might work well with one of his abilities—his Charisma LV6 Bonus Ability, Emotion Weaving: You can vaguely sense the "emotional field" of nearby individuals or groups. How clearly you sense it depends on the strength of their emotions.
You can expend Magic to stir or soothe emotions. By expending a large amount of Magic, you can slightly shift another person's emotions.
Will believed this ability and the Emotional Core of Ancient Magic might work together.
The core had also resonated strangely with Will's Patronus Charm. He could feel that, as long as he activated the joy within the Joy Core, he could keep his Patronus Charm stable in its silver-white stage—a true, pure Patronus, rather than its mutated, joy-devouring stage.
Of course, he could