As one of the finest examples of Bradbury’s macabre writing, “The Jar” sets the tone for the many so-called carnival stories that were to follow. In these stories, carnival imagery is the major source for Bradbury’s discussion of the presence of evil as a threatening force in the world. “The Jar” reveals Bradbury’s belief that the potential for evil as well as for good dwells within each person. The evil nature of the jar is suggested early in this story when the carnival boss admits that he has been having strange thoughts about the jar. Then, the night meetings at Charlie’s are described as a “kind of rude church gathering” where the townsmen sit with “reverent awe” gazing at the jar. Also, the embryo in the jar is depicted as being a “Holy Grail-like thing.” Here, then, the nature of religious worship is juxtaposed with the implied evil nature of the jar, indicating that either of the two is possible. Yet the fantasies that the characters engage in concerning the “thing” in the jar indicate that for them, evil is so strong that it has taken precedence over the good. Implicit is Bradbury’s warning that this disguised evil can be a potent possibility unless humanity is careful to cling to that which is good.