We Only Fear the Unknown

After Wizet used the Petrification Spell Command to transform Regulus Black's locket into a "Spirit-Calling Casket," Kreacher returned to the island at the center of the lake.

"Great Mr. Lovegood, will this jar do?" Kreacher asked, balancing an enormous transparent jar on his head.

By the light of the ring of fire, the jar's unusual nature was apparent; it faintly gave off a purple glow.

"Very pure crystal..." Dumbledore stepped forward a few paces and examined the jar atop Kreacher's head. "The craftsmanship is also superb..."

He reached out and brushed the jar. A golden sheen spread around its mouth, where dense, tiny Runes emerged. "The protective magic is comprehensive as well... I believe it will make an excellent storage container."

"That's wonderful!" Kreacher sighed in relief. Although the jar was protected by magic, he still set it down with utmost care, as though tending to a soft-shelled egg.

Sirius Black and the others also brought good news. Amid a churning sound, Sirius Black emerged beneath the lake's surface, holding Regulus Black's body.

Remus Lupin and Harry stood ready on either side. They had clearly already discussed it and could act at any moment to lift Regulus Black's body from the water.

Kreacher swiftly unscrewed the jar. "Great Mr. Lovegood, Kreacher only needs to fill it with lake water?"

Wizet nodded. "That's right."

Kreacher immediately got to work. He picked up the jar and carried it to the lake's edge, allowing the water to flow inside.

This was his third time entering the cave, and he knew it was subject to some sort of magical restriction. Presumably, this was also part of Voldemort's trap—the lake water could only enter a container this way.

Wizet reviewed his plan and recalled one possibility.

"Headmaster Dumbledore..." he said, looking at Dumbledore. "I suspect