The light that illuminates the truth

Exploration Stage: Historical Museum
From: Mr. Black
Description: Usually, when a suspect is present, we keep him or her under surveillance and wait for him or her to reveal himself or herself. This method will work for the device in question, as long as we can keep our eyes on it. Find a bright light.
Completed: They found the perfect lamp! The crystal inside is extremely bright and painful to look at. Thanks to this, we have a perfect line of sight from the surroundings to this monstrous device.