When Cem (Kerem Bürsin), a soldier in the navy, loses his wife Alara (Devrim Özkan) to cancer, he begins a journey towards the "Blue Cave", the place where he promised to show his great love for her one day. Cem's journey to the Blue Cave; It turns into a surprising discovery that reveals the details of his relationship with Alara and reaffirms that true love is eternal.