To Sleep is told through the journal of Karen Miller, a nurse and student from Philadelphia. The journal begins the night three alien ships appear above Earth. When Karen awakens, she is told Earth was destroyed by a space phenomenon called the Rift and she is to be the leader of a small group of women tasked with assisting their alien rescuers in awakening the four billion or so surviving humans who are in cryogenic suspension.
Each time Karen goes to sleep, she doesn't know exactly what it will be like when she awakens. The line between what is real and what is not real becomes so blurred that Karen and the other women can only trust each other. When reality is finally defined, the six of them learn truths that will forever change not just themselves, but every genetic homosexual on Earth.