The Undetectable Extension Charm had two prerequisites.
One was a precise understanding of space,
and the other was relatively delicate magical control.
When Vincent had shaped that oversized firepower, he had actually barely reached the threshold.
"Your case is made of Mithril, so the consequences of failure won't be too serious."
Dumbledore raised the Elder Wand and pointed it at a large patch of air before him.
As if compressed, a translucent dot the size of a fist quickly appeared.
"Use as much magic as possible to expand its internal volume, folding it all into the original space."
The pale blue glow from the Elder Wand continuously flowed into that tiny dot.
"When you can completely master this technique, you can probably try Apparition."
"Oh." Vincent pointed his wand at the suitcase with a deeply suspicious expression.
Expanding the inner space of a stable object was difficult enough. Expanding unstable air would probably take at least two or three years.
Dumbledore flicked the Elder Wand, covering Vincent's entire body in a translucent film.
"You can begin—"
A violent explosion rang out.
Vincent, who had been blasted more than ten feet away, sat dumbly on the ground.
He had poured all his magic into it at once, and then the entire suitcase had exploded.
Dumbledore came over and held out a hand. "I nearly forgot. You need to establish a few anchor points first, otherwise the unstable space will collapse."
If not for the magical membrane, Vincent would have dared to point at that crooked nose and unleash a stream of profanity.
"Professor, can I swear?"
"No. You need to learn to restrain yourself."
He endured it!
He gathered the liquid Mithril scattered across the ground, and the second attempt began.
He first expanded the eight anchor points of the rectangular