The manga is set in 15th century "P Kingdom". People who suggest ideas in opposition to the teachings of the "C religion", such as that the Earth revolves around the Sun, are considered heretics, and are tortured or burned at the stake. Rafal, a child prodigy with an interest in astronomy, is forced by Hubert, a scholar and heretic, to assist him in his research for the "about the movement of the Earth" theory. When Nowak, an inquisitor, finds a diagram drawn by Rafal showing a heliocentric model, Hubert claims responsibility and is executed, leaving Rafal a spherical pendant. Rafal uses the pendant to find Hubert's hidden research materials on the theory. Rafal continues Hubert's research, but is informed on by his foster father, Potocki. At his inquisition, Rafal refuses to denounce the theory, committing suicide by ingesting poppy seeds.
Ten years later, Okgi and Gallus, two duelists, are assigned to guard a heretic during transportation. The heretic reveals the location of the research to them, dying to protect Okgi from Nowak. The pair decide to seek out a demoted priest, Badeni, to help make sense of the material. While on a bridge, it collapses, and Gallus entrusts their mission and the pendant to Okgi before dying. Okgi meets Badeni, who agrees to look at the materials in exchange for Okgi continuing Gallus' astronomical observations. Badeni finds the materials to be incomplete and requiring the use of more records. They post a problem at public boards in the city and find a girl, Jolanta, answering it on the same day. Jolanta, a researcher, agrees to cooperate with them by introducing them to Piast, an ardent advocate of the Ptolemaic model. After Okgi observes Venus waxing, Piast agrees to give the group access to his records. Using Piast's records, Badeni finishes the theory. Nowak catches on to the group, inspecting Badeni's cabin and noticing the pendant. Okgi holds off the inquisitors, but him and Badeni are captured. Nowak tortures Okgi, forcing Badeni to divulge the location of the research materials, and the two are executed. Antoni, a rival of Nowak, attempts to get Jolanta, Nowak's daughter, convicted as a heretic, but she is freed by an inquisitor. Cklamovski, a priest at Badeni's church, discovers that Badeni had transcribed a diary written by Okgi onto the heads of the local vagabonds.
Twenty-five years later, Schmitt, the captain of the Heretic Liberation Force, retrieves Okgi's book under Jolanta's orders, but is forced to leave it in an abandoned village. Draka, a Romani, comes across the book and, seeing an opportunity to profit, burns it, forcing Schmitt to take her along. Draka, in exchange for being allowed to use their printing press, recites the contents of the book to Jolanta. When the group is found by the inquisitors, Jolanta stays behind, blowing herself up.
