A member of the second Jesuit expedition to the planet Rakhat, John is protagonist Emilio Sandoz's closest friend aboard the Giordano Bruno. This makes him the perfect foil for Carlo Giuliani to blackmail Emilio into cooperating, by threatening otherwise to kill John by putting him out an airlock. John moves away from the delicate landers in order not to damage them when his body explodes in the vacuum. For the first time, he finds himself unable to pray.