A Cross Line summary: Sungyeol loses his mind after stabbing his lover who tried to kill him. It was Jaseong that accidentally saved him. Jaseong allows Sungyeol to stay in his house until the heavy snow stops. That night, Jaseong placed his hands on Sungyeol’s chestnut-like body. Sungyeol seduces Jaseong by telling the man mysterious stories. Here lies the lives of two men whose kept secrets begin to overlap.