Dae-ho (KO Soo) is in agony as his only son has been kidnapped at a theme park. He gives up his career as a journalist in search of his son but to no avail. So-hyun (GANG Hye-jung), Dae-ho's psychiatrist and friend, suggests trying to lucid dream, a new psychiatric healing method. The process involves having a patient fall asleep with the awareness that he or she is dreaming, thus enabling them to recall lost memories to treat traumatic experiences. Instead of using this method as a treatment, Daeho decides to use lucid dreams to search for his son.