Yesterday (2004)

In 1990 number of children suddenly disappear Meanwhile the Ministry of Defense selects an elite group of scientists for a topsecret mission Then 30 years later The year is 2020 on a reunified Korean Peninsula A string of murders is committed against retired scientists The Special Investigations SI unit staffed by a crack team from the former North and South Koreas and outfitted with the latest technology is brought in to investigate The killer however far from being deterred taunts them with a signature pendant at every murder scene In an act of devilish boldness he even kidnaps the son of the investigation teams leader Seok