A dwarf enters a library, looking for a book on levers. He spends hours searching but can't find anything useful. Frustrated, he approaches the librarian.
"Excuse me, do you have any books on levers?" he asks.
The librarian smiles and says, "Sure, let me show you."
She leads the dwarf to a secret room, hidden behind a bookshelf. In the center of the room, there's a single, mysterious lever.
"Here's the only book on levers you'll ever need," she says, gesturing to the lever.
Unable to resist, the dwarf pulls the lever. Suddenly, the entire library transforms into a joke book, filled with running gags about dwarfs and levers.
The dwarf sighs and says, "I should have 'seen' that coming."