Santangel was a good, or at least a decent, man, but one with flaws like other human beings. In his youth he enjoyed learning, debating philosophy and science, but the death of his father left him obsessed with the idea of immorality. He traveled far and wide in search of the secret, always in the company of Tello, his best and most trusted friend. Eventually he is offered a bargain that allows him immorality and he accepts only to later realize that Tello, "twice as learned" as he has betrayed him. Tello's son tests his immortality again and again, and although Santangel feels the pain, he does not die. At Tello's deathbed, he begs to be released from the curse, but is refused. Generation after generation he is held in servitude, finally giving up his association with scientists and librarians, knowing he will never have the opportunity to visit with them. He retires from the world at large but sees a chance for freedom when Victor de Paredes agrees to release him in exchange for someone with even greater powers. He has felt nothing for so long that he is surprised to discover the Luzia who hides behind her scullion demeanor and who makes him remember that he is a man and a very human man. What he might have been without Tello's betrayal is apparent.