"Crack" is centered around Seo Hee, who is haunted by the death of her classmate Ye Ji. Seo Hee excuses herself to the restroom. Once Seo Hee is in the hallway, the audience sees that Ye Ji's photo has a contorted smile. Seo Hee makes her way to the restroom to smoke, she begins to hear noises of someone entering, but there is seemingly no one else in the bathroom with her. Once things seem to be fine again, a ghostly figure appears, covered in blood. The next scene cuts to Seo Hee's body sticking up from the toilet, blood coating the walls and her body. Then it cuts to the poster where Seo Hee's smile begins to upturn further, matching Ye Ji's. (Source: Sxngari at Mydramalist)