Safe

“And that,” the professor concluded, slamming the vault's door shut, “is the MagnaSafe. Unbreakable. Uncrackable. One-of-a-kind.”

“How do you open it?” the reporter asked.

“Oh, it's a simple lock-and-key mechanism—let me...” He patted his pockets. Once. Twice.

“Damn. Damn. Damn,” he spluttered, red-faced.

“What?”

“Left the keys inside.”