Sewon, a research-obsessed brain scientist, gets devastating news that pushes him to advance a risky brain-sync system in search of answers.

Intel from a private investigator drives Sewon to conduct more brain syncs, leading him to believe his wife, Jaeyi, was right about their son Doyoon.

Sewon's investigation makes him a target, and he discovers a disturbing truth about the private investigator that rocks both their worlds.

Heejin, the daughter of a man connected to Jaeyi, sheds new light on Sewon's home life and shares more details about what happened to Doyoon.

Sewon confronts the mastermind pulling the strings behind his ordeal and setting in motion the diabolical plan involving him and his family.

Harnessing the power of his unique brain and the knowledge of those he synced with, Sewon risks his life to save his family. Season finale.