Although somewhat humorless, Father Ruiz-Sanchez is one of the more engaging protagonists in the science fiction of the 1950s, perhaps because the genre literature of that era contains so few sincere portrayals of characters who are both intelligent and religious. Despite James Blish's insistence that their moral code is too close to that of Christianity for coincidence, the Lithians are a nicely developed alien race and the one normal Lithian readers meet, Chtexa, the father of Egtverchi, comes across as a believable but distinctly alien individual, something much more than merely another human being in a funny costume. In Egtverchi, Blish attempts something particularly difficult, a sort of intellectual half breed. Egtverchi, although raised by humans, cannot, because of his genetic heritage, be fully human and, moreover, does not want to be. An absolute outsider, estranged from both Lithia and Humanity, he swings rather schizophrenically, but quite believably...