George is an incredibly average, unobtrusive man living in an overcrowded, rain-soaked Portland, Oregon. He uses drugs to suppress his sleep because his deep dreams have the power to seamlessly alter reality backward in time. Fearing this immense ability, he lives a passive life and seeks to abstain from causing any further unintended consequences.

Dr. Haber is a large, physically imposing dream-specialist psychiatrist who quickly discovers George's reality-altering abilities. Driven by utilitarian ambition, he views George as a tool to fix the world's macro problems according to his own subjective vision of the greatest good. He uses an experimental machine called the Augmentor to direct George's sleep, aggressively pursuing the power to reshape society.

Heather is a pragmatic attorney who initially views George as weak but soon recognizes his quiet integrity. As a Black woman shaped by her activist mother's struggles, she projects a tough exterior to succeed in her field. She becomes increasingly invested in investigating Dr. Haber's experimental, unauthorized use of the Augmentor machine on George.

The aliens are nine-foot-tall extraterrestrials who wear suits resembling giant sea turtles and speak in toneless voices through a device on their left arms. Originally manifesting as a threat due to the wording of Dr. Haber's dream suggestions, they eventually integrate into human society as compliant merchants. They possess a deep, philosophical understanding of time and dreams.

Penny is the office assistant at Dr. Haber's psychiatric practice. She handles his schedule and manages the administrative duties of his office as it expands from a small practice into the sprawling Oregon Oneirological Institute.

Mannie is the manager of the building where George lives at the beginning of the story. He oversees the dilapidated housing arrangements in the overcrowded, resource-starved version of Portland.