According to Douban Movie Query, in the TV series "Squid Game", the surprise in the third episode is that in the game, Sung Ki Hoon discovers a secret, which is about Wu Yi-Nan and Sung Ki Hoon. In the game, Oh Yi-Nan and Sung Ki-Hoon are a pair of partners and they complete many missions together, but Sung Ki-Hoon never knew about Oh Yi-Nan's relationship with himself. In the third episode, Sung Ki Hoon discovers a secret which is about Wu Yi-Nan and himself when he was a child. It turns out that they were childhood playmates who were separated for some reasons and now they meet again.