The cartoon adventures of a ten-year-old girl who solves ghoulish mysteries. In Sunworshippers, a model seduces the town into joining her new trendy tanning club. Mona discovers the model to be an ancient Aztec Sun Goddess who wants to rebuild her empire and make the townspeople her slaves. In The Columbus Triangle, after a radio transmitter causes strange sonic disturbances and the transmission of strange public service announcements, Mona suspects that the town's polarity has been altered.