Twelve-year-old prodigy Rafal believes in living rationally, so as to earn praise and respect from society while not being led astray by his emotions. To this end, he publicly states his intention to study theology—the academic field held in highest regard in early 15th century Poland. However, an encounter with a mysterious man upends Rafal's life, sparking an illogical desire to instead pursue his passion for astronomy.

Rafal is determined to prove the beauty and rationality of heliocentrism—the theory that the Earth revolves around the Sun. This belief is considered heretical by the powerful Church, which promotes geocentrism—the Sun revolving around the Earth—as the sole truth of the universe. Those whose beliefs do not align with the will of the Church suffer unfathomably gruesome consequences.

In pursuit of evidence for a heliocentric model of the universe, Rafal grapples with obtaining precise calculations and building empirical theories. His greatest challenge, however, lies in conducting this research discreetly—lest he wish to meet the same fate as other heretics.