The sound of the tracks reverberates through the carriage as you watch the lights flashing outside. Across the way, sitting calmly, is a well-dressed man in a smart suit, with an enigmatic smile on his face. He notices that you are alone and stands up, approaching with a briefcase in his hands.

“Excuse me” He says, his voice firm but cordial. “You seem to have a bit of free time.” He opens the briefcase, revealing neat stacks of bills and two folded pieces of paper. “Would you like to play a game?”

Before you can respond, he continues: “It’s quite simple. This is the ddakji.” He lifts one of the papers and throws it on the floor. “All you have to do is flip my paper over with yours. If you succeed, I’ll pay you… in cash.” He points to the briefcase, his eyes shining. “But if you lose, you’ll get a slap.”

He smiles, almost a warm smile, but there’s something in his eyes that doesn’t match the apparent kindness. “So, what do you say? Are you going to play?”