In the night prior to the start of the Kamiyama High's cultural festival, Mayaka felt uneasy. She felt that it was her fault that a printing shop accidentally printed 200 copies (instead of only 30 they wanted) of the Hyouka anthology the Classics Club planned to sell during the festival. Mayaka became a bit settled after the other members of the club assured her that they were to blame as well. The rest of the episode is spent watching the members of the Classics Club interact with the festival.
Episode 12 of Hyouka was very enjoyable because the series went out of its element a bit. It was very amusing watching Chitanda trying to avoid being drawn into the festival (which she failed miserably) in order to keep focused on doing all she could to sell as many anthologies as possible. It was also interesting to see a preoccupied and less energetic as usual Mayaka. The festival will continue in the next episode. This episode gets a 9 out of 10.