The Anchor Paradox. The Memoryline Cycle, #1

At 3:14 every morning, the background radiation of the universe goes silent for forty milliseconds. Ethan Maddox, an isolated, brilliant physicist at MIT, is the only person alive who notices - and noticing is the first mistake that unravels everything. The silence is a seam: a flaw in a reality that is not supposed to have any. When an experiment in a basement lab kills Ethan and he wakes into a version of his life that is too clean, too kind, too perfectly arranged, he begins to understand the truth a piece at a time.
He is living inside a flawless copy of his own world - a cradle - built and maintained by post-human engineers who abandoned their bodies long ago. Two universes are dying, torn at a shared seam, and a single human consciousness, anchored by something it loves, can hold them together. Provided it never learns what it is. They gave Ethan a curated life. They gave him Sophia, a woman calibrated to his every loneliness.
They gave him something to lose - and they did not expect her to become a real person, or to wake him. What follows carries Ethan across the seam into a scarred alien world, through a resistance of cybernetic survivors, and at last against Voss: a calm, reasonable adversary who was once a man like Ethan, and who chose control over freedom. To hold two worlds together, Ethan must prove the one thing his makers spent four thousand failed attempts trying to engineer away - that consent, freely given, is stronger than any cage.
Literary science fiction for readers of Blake Crouch, Andy Weir, and Jeff VanderMeer. Book One of The Memoryline Cycle.