Hyouka (2012) - S01E08 - Let's Go to the Screening
The episode starts with Chitanda chatting with one of her upperclassmen. During this conversation the Classic Literature Club is invited to see a mystery production of class 2-F, whose script writer got seriously ill before she could finish the story so the murderer in the story is unknown. Houtarou does not really feel like taking part in the detective work but in the end agrees on their playing the part of observers listening to the three amateur "detectives" of class 2-F and after that giving their opinions.
(Source: Wikipedia)