Brother and sister Merrie and Joey visit the carnival at the invitation of their cousin. A trip into the House of Mirrors makes them realize things are not what they seem. Things that appear truthful are not always so, which makes these curious siblings wonder, "What is Truth?"

They soon meet an unusual friend: a beautiful, wise white unicorn named Providence. Together, they journey to seek Truth. They look in many places. They search through the printed word, the media, and the opinions of their peers. The children even investigate the truth of drugs, magic, and emotions.

Eventually, with Providence's help, Merrie and Joey learn of the ongoing war between the great Truth Maker and the Truth Hater. They must choose a side in this war, and the decision they make could lead others to Truth or into darkness.