In 1996's The Sparrow, Mary Doria Russell's unexpectedly popular first novel, the author took a classic science-fiction plot—first contact with an intelligent alien species—and added an unlikely twist: Inspired by the 1992 controversy surrounding the 500th anniversary of Christopher Columbus' arrival in America, Russell made her interplanetary pioneers Jesuits. A premise as implausible as it was ripe with opportunity, the decision gave the former anthropologist a chance to explore issues of history, faith, and society, mostly as interpreted by complicated Jesuit protagonist Emilio Sandoz. Readers of The Sparrow will recall that the mission to Rakhat, an inhabited planet whose radio signals had been intercepted on Earth, ended badly. Only Sandoz returned to Earth, his faith shattered after witnessing, being subjected to, and at times even committing the cannibalism, slavery, murder, mutilation, and gang rape that were institutionalized among Rakhat's two intelligent species. Children Of God, Russell's sequel to The Sparrow, opens with Sandoz still plagued by feelings of guilt, believing that a combination of his own incompetence and God's cruelty led to the failure of the mission. Naturally, few on Earth are content to let him be, and just as he believes he's begun to come to terms with what he's experienced, Sandoz is whisked away against his will, kidnapped by a group of priests and gangsters, each with their own reasons for going to Rakhat. As rich as its predecessor, Children Of God nicely expands upon the issues raised by The Sparrow. One of both books' great strengths—aided by Russell's background in anthropology—is the way they examine ethical and religious questions while withholding judgment. It helps that Russell has excised the too-cute dialogue that occasionally hampered The Sparrow: One of that book's great mysteries was how the author could create such memorable, well-developed characters and often make them speak in banal exchanges. Russell seems to have grown as a writer, but it could simply be that the giddiness of discovery is absent among the characters of Children Of God. While its predecessor was about what happens when cultures encounter, get to know, and (sometimes fatally) misunderstand one another, Children Of God is about the more complicated matter of what happens next. Though this occasionally makes it a bit Byzantine, especially in its second half, Children Of God is far from a disposable sequel. With The Sparrow, Russell created a fascinating, thought-provoking, open-ended piece of work; with Children Of God, she does a satisfying job completing it.