Shrike

But high overhead the Resurrected Man tunes his eyes to ultra-red and switches on his heat sensors and sees two glowing human shapes amid the soft grey static of the trees. “TAKE ME CLOSER, ” he orders.

“If you can see them so clearly now,” the airship’s pilot grumbles, “it’s a pity you couldn’t tell that bloomin’ balloon was empty before we went chasing it across half the Hunting Ground.”

Shrike says nothing. Why should he explain himself to this whining Once-born? He had seen that the balloon was empty as soon as it popped back up above the clouds, but he had decided to keep it to himself. He was pleased at Hester Shaw’s quick thinking, and he decided to let her live a few more hours as a reward, while this slow-witted Engineer-aviator pursued her empty balloon.

He flicks his eyes back to their normal setting. He will hunt Hester the hard way, with scent
and sound and ordinary vision. He calls up a memory of her face and sets it turning in his mind as the airship sweeps down through the fog.

Mortal Engines, Chapter 15, the Rustwater Marshes. pg 60/152


The doors swung wide. The room beyond was big and dark. Grike's new eyes
switched automatically to night vision, and he saw that the far wall had been reinforced with armor plate. One long slot of a window, like the slit in a visor, remained open, glassless, gazing
toward the west. The figure who stood at it was not entirely human. "Your Excellency ..." Popjoy said.

Infernal Devices, Chapter 6: We are making a new world, pg 37/237