After the success of the smart patch "Hatch" presentation, Jaehyun gets touted as the presidential candidate. Meanwhile, his wife Taera regains her lost memory. Taera and her neighbor, Haesoo, pursue an unsolved case.

Taera cannot believe she is No.50, the killer who shot Haesoo's father fifteen years ago. Chaos ensues at Hatch as super chimpanzee Red gets killed. The three friends of Hatch start their investigation.

Jaehyun declares his candidacy for president, and Kim Seonduck finally appears. Taera gets thrown into commotion from her past and present. Worried about Taera not acting like herself, Jaehyun hires a bodyguard.