Tess Morton is a middle school teacher. Her students constantly ostracize their classmate, Matthew. Despite her best efforts, Tess can’t help but see him as a sniveling crybaby. One day, she and another teacher, Yvonne, take their classes on a field trip to a tin mine. At the facility, a commotion breaks out between Matthew and another student named Jason. Jason was taunting Matthew with a bird carcass, and its blood got on Matthew’s face. Tess begrudgingly makes Jason apologize. Then, the tour guide, Mr. Hardacre, herds them all into an open-air train to go underground. As they descend into the darkness, Tess feels uneasy. Mr. Hardacre tells the story of Michael Rowan, the son of a nineteenth-century mine manager. Michael, a known bully, fell into an abyss after chasing a boy named Luke into an unsupervised area. Michael’s father blamed Luke for his son’s death, and the boy soon disappeared. Years later, excavators found Luke’s skeleton near the mine. Mr. Hardacre turns out the lights to show the children how dark it would have been in the mine before the invention of electricity. When the lights come back on, Jason has smeared black dirt all over Matthew’s face. Just as Tess is about to reprimand him, the lights suddenly go out again. Mr. Hardacre turns on his headlamp to find that Matthew and Jason have vanished. Panicked, he and Tess get out to look for them. They find a filthy, trembling Matthew among the rocks. He says Jason called him “Michael” before he disappeared. After a few more minutes, the small light illuminates a chilling sight: Jason’s skeletal body, black dust bleeding from his eye sockets.