After their summer adventures, the children of the group who solved the mystery with the three keys in Salamis are traveling to Kastoria for a few days.

They will meet new friends, as well as a grandmother who knows all the legends of the area, making their stay more exciting. However, strange events do not seem to leave them alone.

A mournful shadow on the shores of Dispilio, an ancient symbol that seems to come to life, and a pendant hiding secrets of thousands of years lead the children on a new journey full of riddles, discoveries, and unexpected allies.

From Lake Kastoria and Dispilio, to Néstorio and the stone bridges, the past awakens.

Within a few autumn days, the children will embark on a new quest: for a woman in an unknown time, for a truth that was never recorded, and for a figure who perhaps wants to trust them, because some secrets are better left buried.