OO Magic Episode 9: The Magic that Brings Good Luck - Part 2 - S0.E10

Frieren's Party encounter three treasure chests. Fern cautions that at least one of them must be a mimic, so Stark suggests using the magic that brings good luck. The first chest contains gold and treasure, and the second chest contains a rare grimoire. To their dismay, Frieren insists on opening the third chest, which is a mimic. She gets caught and yells that it is dark and scary inside, and Fern wonders if Frieren did this on purpose.