Bryn Llewelyn spends his life strung out on too much caffeine, fighting sleep at every turn. He can barely hold down a part-time job as he lurches from day to day, perpetually exhausted.

He is trying to avoid Somnus, the dream world where people like Bryn—dreamwalkers—roam during their sleeping hours.

Bryn has been dreamwalking since he was child. He's never found navigating Somnus easy, but lately it's become much, much harder. Each time he manifests in Somnus, he is helplessly drawn to a sinister tower. Something evil is imprisoned there—something that wants out—and every time Bryn falls asleep, he finds it more difficult to resist its lure. Not to mention the compelling man who patrols its walls…Laszlo Grimm.

As a teenager, Laszlo Grimm suffered from a sleep disorder so profound, his family had him locked up for treatment. Whilst the brutal "therapy" he underwent was successful, Laszlo paid a steep price for it—his ability to feel emotion. Now, for the first time in years, Laszlo's night terrors are returning, and with them, his fears about being locked up again.

When Bryn and Laszlo meet in the real world, Bryn recognises Laszlo as the man he has already met in Somnus, but not only does Laszlo not know Bryn, he can't even remember any of his dreams.

Bryn fights to open Laszlo's eyes to the truth but Laszlo cannot quite shake the conviction that his old condition is catching up with him...not least because Bryn Llewelyn is awakening emotions in him he hasn't felt in years.