A group of youngsters get a permission from the mayor to restore an old building to make it a youth cultural center. Workers find a skeleton in the building. And the youngsters find a bag with letters which have never been delivered.
A woman visits the building saying she is touched to come to her childhood house after years. But Magda suspects she's lying because she was seen the week before. During the night someone breaks into the building.
Reading another one of the "lost letters" leads the 5 friends to meet an old-fashioned romantic writer who claims he has murdered a younger modern writer he despised.
Another letter leads the group of friends to visit the correctional facilities in order to resume efforts for an innocent man to be released and for the guilty one to be imprisoned.
The 5 friends deliver a letter to a man who later is arrested for the murder of his brother. But is he really guilty? And if not, will the group of friends find the murderer?
One of the letters refers to a Greek in USA under the nickname "Johnny the cat". Meanwhile Magda invites 2 of her old schoolmates to set a pirate radio station in the youth cultural center. One of them has the nickname "Johnny the cat".
One of the letters has no sender's name and contains only a photo of a photographer. When the group of friends deliver it to him, he recalls an incident when he became witness of a suicide.
Lefteris takes photos of passers-by for a photo contest. One of them shows a woman outside a house. She happens to be the wife of the professional photographer who helps for the contest. When she disappears he visits the house.
An anonymous warning letter made out of cutout letters from newspapers, seems the perfect one to fit with the murder, the skeleton and the theft of the letters. It leads the five friends to a person with a disability.
