The explosion swept through almost half the Library.
Su Er instinctively flung a pale blue shield in front of himself. The shock wave battered him from side to side, and the Shield Charm before him teetered on the verge of collapse.
Fortunately, Hermione was still in another space and was not caught in the blast.
After the explosion subsided, the book floated in midair, covered in cracks. It no longer shone, and there was nothing special about it at all.
In a flash of inspiration, Su Er raised his wand and gently touched its tip to the "key."
It silently shattered into specks of stardust that drifted down.
Then Su Er felt a hook behind him give him a hard tug. The damaged shelves and the books scattered across the floor swiftly returned to where they belonged. It all happened in an instant.
"Su Er?" Hermione's voice rang out. "What are you doing here?"
Su Er looked at Hermione, who stood before a bookshelf, about to put a book back. This was bad. The blast had swept the Invisibility Cloak aside, leaving him fully exposed before her.
But before Su Er could respond, Hermione suddenly closed her eyes and fainted.
There was a soft thud.
"Who's there?" Madam Pince's voice rang out the next moment, accompanied by hurried footsteps. Before Su Er could feel relieved at Hermione's fainting, his heart leaped into his throat. If Madam Pince discovered them, what followed would certainly not end well.
Su Er hurriedly picked up the Invisibility Cloak from beside him and rushed to Hermione. Crouching, he took her limp arm and draped it over his shoulder, then pulled out his pocket watch with his other hand.
Madam Pince's feet had already come into view, and she would round the corner in another second.