AC means

Exploration Stage: Foggy Oasis
From: Kira Woodville
Description: It seems that Dr. Barry had a plan to use the fog to accomplish something spectacular. To find the core of her research, let's find the reaction vessel. According to her journal, she was studying the chemical reactions that occur between fog and various substances in reaction vessels. Do you have any idea where to find them?
Completed: That is a very big reaction jolly. Dr. Barry's notes record that she was using this device to train the fog to learn the presence of creatures and avoid them. This was apparently to reduce the danger of walking through the fog. Let's reproduce the experiment.