Schrödinger's thriller; there both is and isn't a kidnapped child, there both is and isn't a murder, there both is and isn't a jealous drama tearing a marriage apart, there are two physicists arguing the nature of reality, there are two detectives trying to figure out not only what's happened but what happens. Zeh has her characters speaking in epigrams as usual, but she's good enough and her characters self-involved enough to make it work.