Five members of the mountain bike club, Sangaja. To ride a mountain bike, we head to Chiaksan Mountain, where Min-joon's Uncle villa is located. After arriving at Chiaksan Mountain and enjoying the ride, strange things began to happen to the party…. And something unidentified chasing them! A desperate survival game for Sangaja's party to survive on Chiaksan Mountain begins.

Mount Chiak

Yoon-seok, Sang-woo, Won-seon, Ho-young are 4 best friends living in Susaek, the poor town in Seoul. Having the waste landfill nearby, Susaek is full of smells and trucks carrying the metropolitan garbage. When Korea holds the 2002 World Cup, Susaek is mentioned for the place of new soccer stadium. Rich dealers crowd into the town and villagers get excited for the hope of redevelopment. Meanwhile Won-seon is recruited by the regional gang and gets involved in the redevelopment business, and the petty jealousy of Sang-woo cracks down their friendship…