In the final episode of the Cille series, 15 years after Kayra handed over the crown to Rehzen, a tribe from the seas brought technology to the world of humans and Ezakis. After making humans and Ezakis dependent on technology, the tribe, wanting to reap the rewards, organizes a final feast to take over all of Cille. To prevent the loss of the Cilles, the last hope for a world depleted of energy resources after a nuclear war, Kayra and his friends are forced to wage a major war against this tribe in the year 2069.

The screenwriter of the Istanbul Guardians series is busy preparing for the new episode to be released. When his boss asks him to write an episode introducing the Gümüşçüler Çarşısı (Silversmiths' Bazaar), he goes to Veli Dede's shop to do some research. The young woman finds herself in the midst of a great mystery at the shop she went to for research. According to the stories, there is a hidden treasure beneath Istanbul, and the secret of this treasure is entrusted to the silversmiths. Veli Dede is the last guardian of this treasure. The treasure is not a valuable stone like gold, diamonds, or rubies, but a life-giving water that heals those who drink it and keeps them from aging. After learning this, Aslı embarks on a mysterious adventure.

At the 100. years of opening of the Great National Assembly, Gürgen and his apprentice Azmi travelling in the time and trying to block opening of the assembly. Let's see if the Istanbul Guards can stop them this time.