A relentless machination.
Rich young people are invited to a party in a luxurious residence in an upscale neighborhood, on the mountains overlooking Seoul. Each one is asked to choose a mask: one becomes the Bear, another the Fox, another Tom Cruise or Pikachu. Fine buffet, expensive alcohol, various drugs. Couples are improvising in the rooms upstairs when suddenly a gun goes off and one of the guests collapses, shot at point-blank range.
Everything changes for the first time: the guests are kidnapped. A ransom demanded in diamonds is quickly collected by the families of the hostages.
As the negotiations progress, the liberations follow one another. Until there is only one group of seven people left. The hostage situation takes another turn when the kidnapper announces that the last hostages will be tried for their involvement in an unpunished crime, the rape and murder of a young girl nine years earlier.
And this is only the first twist in a dark and inexorable plot.