" Demons, to you, are hideous creatures that leap out from the shadows to rend and attack. And there are such creatures. But there are also demons of deep subtlety and secrecy, demons who walk among humans unrecognized and unhindered. Yet I have seen them do such dreadful things that their more bestial colleagues seem gental in comparison. "

― Cassandra Clare , City of Ashes (The Mortal Instruments, #2)