Each of the five stories featured in this collection explores the precariousness of life. Presented to the reader as documentary summaries and scientific reports, they are beautiful in their simplicity, leaving the reader haunted and unsettled. The title story presents scientific research findings about a species of winged mice that are unable to fly and, whilst breeding, shed tears but then die, leading their species to extinction. Eerily, the scientists conducting the research both die from incurable diseases in the process.