Imagine a race of marsupial-like aliens who have not two, but three sexes: father, birth-mother, and nurture-mother. The difficulties of married life are further complicated by adding another partner, but this culture has worked out its own unique solution. The arrival of a new race of space-faring aliens, however, will change everything.

Author James Patrick Kelly is a two-time winner of the Hugo Award and a 2007 Nebula Award winner. His stories appear frequently in Asimov's Science Fiction, and he writes the magazine's "On the Net" column. Publishers Weekly has called him "a meticulous craftsman in the demanding short-story form".