 As the story reaches its climax, the antagonist is
But ever since the engines somewhere in the rear of the world had changed their tone, from the steady whining Rikud had heard all twenty-five years of his life, to the sullen roar that came to his ears now, the feelings had grown. Something loomed there in the port, so huge that it spread out over almost the entire surface. Rikud turned again to the port, where he could see nothing but an obscuring cloud of white vapor, murky, swirling, more confusing than ever. Now if the world had walked from—somewhere, through the vast star-speckled darkness and to the great garden outside, this also was purposeful.
 Crifer, the only person Rikud ever thought of as a companion.
 Wilm, who appeared out of the blue.  The garden, because it holds so many evils for the characters as they enter.  Chuls, as it had been from the story's rising action.  Crifer, the only person Rikud ever thought of as a companion.