“there is a fine line between sarcasm and hostility, you seemed to have crossed it. What's up?”

“Keep up," said an irritable voice in her ear. It was Jace, who had dropped back to walk beside her. "I don't want to have to keep looking behind me to make sure nothing's happened to you.""So don't bother.""Last time I left you alone, a demon attacked you," he pointed out. "Well, I'd certainly hate to interrupt your pleasant night stroll with my sudden death."He blinked. "There is a fine line between sarcasm and outright hostility, and you seem to have crossed it.”

“Seems to me that there is a fine line between insanity and dedication…I call that line commitment”

“It is a fine line, in all of us, between civilization and savagery. To any who think they would never cross it, I can only say, if you have never known what it is to be utterly betrayed and abandoned, you cannot know how close it is.”

“She radiated pure hatred; a hatred that could only develop when you love someone - the fine line between love and hate had been crossed.”

“There's a fine line between genius and insanity. I have erased this line.”