" Was it a test?” she asked. “I mean, I know I'm still new to this. I'm still the rookie. Did you hang back to test me, to see if I'd be able to handle it alone?”
“Well, kind of,” he said. “Actually, no, nothing like that. My shoelace was untied. That's why I was late. That's why you were alone.”
“I could have been killed because you were tying your SHOELACE?”
“An untied shoelace an be dangerous,” he said. “I could have tripped.”
She stared at him. A moment dragged by.
“I'm joking,” he said at last.
She relaxed. “Really?”
“Absolutely. I would never have tripped. I'm far too graceful "

― Derek Landy , Playing with Fire (Skulduggery Pleasant, #2)