how & what

Han Sung-joo graduated early from Seoul National University's law school and, from the last generation to pass the old national bar exam, became the youngest judge in the country. No lobbying or emotional appeal can sway him — he is the last hero of his time. Then an anonymous letter arrives. The guests who received the same letter gather on an island with nothing but a single mansion, where only a trembling butler awaits them: a judge, a criminal video analyst, an organ transplant coordinator, a braille press operator, a Catholic friar, a former detective, a horticultural consultant, a drug trafficker and an idol singer. They are told they will vanish one by one in time with the nursery rhyme “Ten Little Soldiers” — and even after they are released, their numbers keep dwindling. “The lightest sins go first.” Someone has set the rules, and is killing by them.