The Catalogue of the Universe, one of the most realistic of Mahy's novels, follows high school senior Angela May's search for her father, a man who has assumed a romantic aura in Angela's mind as a result of the stories her mother Dido has concocted. Dido wishes to protect Angela from the fact that Roland Chase, Angela's father, never really cared about them. Angela is determined to confront him, believing in the romantic notion that he and her mother will be reunited and that she will have a real family again.

She and her friend Tycho Potter forge an increasingly strong relationship with one another, each complementing and reinforcing the other's strengths and weaknesses. In marvelously evocative prose, Mahy provides a mythological and scientific framework for a work about a young woman and a young man who are confronting the issues of growing up, of becoming independent, and of forming relationships outside of family. They find sources of inspiration in the ancient Greek Ionian philosophers, romantic books and films, Greek myths, and the wonders of the universe. Science is not a dry, fact-filled exercise, but an adventure in imagination as Tycho and Angela search for clues to solve the mysteries they face in the world around them.