Kang Si-eun is no stranger to hardship. For years, she's lived alone, cut off from her family, and fought to survive in a world that seems determined to break her. With mounting debt and no way out, a strange game offers a dangerous but tempting chance to escape her struggles once and for all. What Si-eun doesn't know is that her brother, Kang Dae-ho, has also entered the game. As the deadly competition rages on, Si-eun must face the challenges of the games and decide if she can trust the brother she hasn't seen in years - or if survival will drive them apart for good.