Imagine it’s nighttime. You slip under the covers and turn out the light. Maybe you hear cars honking in the street, or voices from the other side of your apartment wall, or your partner snoring beside you; maybe it’s quiet. It might even feel like the whole world is drifting off with you.

But out in that dark night, while most people are fast asleep, there’s a whole world of people who are wide awake. They go to work, drive around, run errands at 24-hour stores. In this parallel universe, there are rarely crowds, nor traffic, nor lines; no awkward shuffling around other shoppers in the grocery aisle, no run-ins with neighbors or cacophony of email notifications. As the sun rises, these nocturnal people settle down to sleep.

They don’t all want to live this way. Some of them have to; they have sleep disorders, or night-shift jobs. But some of them want this very much—enough to seek out those night shifts, to train themselves to wake in the dark. They do this because of the isolation, not in spite of it. I talked to people who painted me a magical picture of their nighttime world: of exquisite, profound solitude; of relief; of escape.