Cat's Eye targets the "Purple Orpheus", the special exhibit piece of the newly-opened Shimazu Museum. Unbeknownst to them, the amethyst is actually a bait to lure them inside. Although Rui is somewhat suspicious of the lack of security in place and non-publication of the Cat's Eye notice, Hitomi and Ai sees nothing but a good opportunity. However, the museum is riddled with deadly traps set by someone bent on revenge, and a pressure-activated bomb becomes the ultimate test for Hitomi and Ai.