Hyun-tae, In-chul and Min-soo have been best friends since childhood. Their relationship is forever changed after Hyun-tae's mother asks In-chul to commit insurance fraud by destroying her arcade.
Jiwon, a motivated new police officer, is strangely bothered after meeting Osun, a social worker. On a hot summer day, a kidnapper sends a message saying, ‘If you want to save the kidnapped child, donate money to the welfare center.’ The incident becomes a national concern as the media report it. Somehow, Jiwon doubts the link between the case and Osun.