A partir de la visita de un alienígena a un museo de la ciencia, empieza una insólita investigación que pretende demostrar la existencia de Dios. El paleontólogo Tom. D. Jericó descarta, por principio, la intercesión divina en cualquier controversia científica, hasta el día en que le descubren un cáncer terminal y debe enfrentarse a su propia finitud. ¿Podrá entonces sostener sus tesis racionalistas sobre la inexistencia del Creador? / His new novel concerns the appearance at the Royal Ontario Museum in Toronto of a spiderlike alien paleontologist named Hollus. The alien has come to Earth to study the five great extinction events that have hit our planet over the eons, the best known being the asteroid collision that wiped out the dinosaurs. When the museum"s head paleontologist, Tom Jericho, consults with the alien, he is shocked to discover that Hollus has proof that her own planet and that of another alien race suffered a similar series of five catastrophic events at virtually the same times as Earth did.