Kress (Dogs, 2008, etc.) returns to science fiction with this yarn about alien contact, genetic engineering and life after death.
In the near future, aliens arrive on the moon and announce that they must make amends for a grave injustice they caused the human race 10,000 years ago. To that end, these Atoners need 21 Witnesses who will travel to seven planets seeded with human stock by the Atoners. In due course, Italian-English grad student Lucca and waitress Cam are chosen to visit Kular A and B respectively; mission controller Soledad remains in the mother ship and remotely pilots shuttles for Lucca and Cam. Cam encounters a monolithic, brutal and appallingly bloodthirsty culture where a game, Kulith—something like chess, monopoly and poker all rolled into one—determines everybody's destiny. On Lucca's planet, meanwhile—altogether a gentler, more peaceful place—evidence mounts that the people can perceive and converse with the recently dead…an explanation Lucca rejects. Once all the witnesses return to Earth, a compelling picture emerges: on half of the planets visited, the inhabitants can indeed see and chat with the recently dead. The Atoners explain that those inhabitants carry a gene that allows them to do so. On the other planets, and Earth, the Atoners deleted the gene. (They don't explain why.) On gene-less Earth, chaos ensues, as Kress skillfully explores the consequences of her ideas, evidently with sequels in mind.
Arrestingly ambiguous and persuasively set forth—in the best science-fiction tradition, guaranteed provocative no matter what your personal opinions.