Ellie is on her way to visit her comatose mother when her sister sends her to repair physics. Each universe has skunkworks that generate the universe within it, making this multiverse a set of matryoshka dolls. The skunkworks that generate this universe have become faulty, and the physical constants suddenly...aren't. In order to fix the skunkworks, to make physics self-consistent again, and to make the world work as it's supposed to, Ellie will have to remember everything her mother has taught her.