You bit de Quincey," he said. "You fool. He's a vampire. You know what it means to bite a vampire."
"I had no choice," said Will. "He was choking me."
"I know," Jem said. "But really, Will. Again?

I promise to charm the dickens out of him,' said Will, sitting up and readjusting his crushed hat. 'I shall charm him with such force that when I am done, he will be left lying limply on the ground, trying to remember his own name.'
'The man's eighty-nine', muttered Jem. 'He may well have the problem anyway.

When Will says 'enterprising', he means 'morally deficient.'"
"No, I mean enterprising," said Will. "When I mean morally deficient, I say, 'Now, that's something I would have done.

Do you think Charlotte will let me handle the investigation?"
"Do you think you can be trusted in Downworld? The gaming hells, the dens of magical vice, the women of loose morals..."
Will smiled the way Lucifer might have smiled, moments before he fell from heaven. "Would tomorrow be to early to start looking, do you think?
Jem sighed. 'Do what you like, William. You always do.

Will: "Nice place to live, isn't it? Let's hope they left something behind other than filth. Forwarding addresses, a few severed limbs, a prostitute or two ..."
Jem: "Indeed. Perhaps, if we're fortunate, we can still catch syphilis."
"Or demon pox," Will suggested cheerfully, trying the door under the stairs.

A sort of good-bye without saying good-bye," he said. "It is a reference to a passage in the Bible. 'And Mizpah, for he said, the Lord watch between me and thee when we are absent one from another.