Ambrose allegory
The issue of Ambrose addiction is literally a metaphor for drug addiction but on a larger scale it is an allegory for gaining power over a group of people by using the tactic of beating them at their own game, using their power and strength against them. In this case the wights literally use peculiars' own power to turn it against peculiars.
Mind is a machine metaphor
In their conversation in chapter two as Sharon is leading them to the Devil's Acre loop Emma and Jacob compare their minds to machines in order to make some light of the bad situation:
“It’s a completely mad idea, I know. But my brain is a hope-making engine.” “I’m so glad,” I said. “Mine is a worst-case-scenario generator.”
Exhausted soldiers simile
When they entered the Devil's Acre loop Jacob is stunned by the look of the architecture and wonderfully compares it to a row of exhausted soldiers.
"Nowhere in their sagging and rotted architecture could be found a single straight line. They slouched like a row of exhausted soldiers who’d fallen asleep at attention; it seemed the only thing keeping them from tipping straight into the water was the tightness with which they were packed..."
Mouse in a trap simile
Going down the bridge towards the wights' fortress Jacob feels like the whole set up is a trap. The fortress seems too easy to approach and enter so there's got to be some catch.
"I felt sure something was about to swoop down and we’d have nowhere to run. I felt like a mouse scurrying toward a trap."
Compliant mare simile
Jacob entered the fighting pit in order to retrieve his old hollow that actually unexpectedly survived and bring it to Mr. Bentham. He re-establishes his control over the monster and is confident in it.
"I’d had nothing to worry about; reestablishing the connection was as easy as picking up the reins of an old compliant mare."
Connection to hollows as an online system simile
In Caul's fortress Jacob fell into a pit full of hollows and established a connection with all of them so he compares it to an online system.
"Something about shutting down all our minds at once, then bringing them back online together—a collective reboot—had brought us into a kind of harmony, allowing me to tap into the unconscious heart of my power, as well as into the hollows’ minds at just the moment their defenses were down."
Mad doctor from Gothic fiction simile
Even though things aren't looking up for the peculiar group and just as they were about to win the fight Bentham betrayed them and sided with his brother. Jacob is finally able to get a good look at Caul and upon doing it he makes this connection:
"He looked flamboyantly insane, like some mad doctor from gothic fiction who’d performed too many experiments on himself."
