Riddles for survival

Why on Friday, the thirteenth, guests arrived in the cottage? Why does the hostess behave suspiciously? What secret unites people who want to forget their past?
... Nelka asked Alice to help prepare a festive dinner in a country house. Alice agreed, which she later regretted. In the midst of celebrations in the cottage, strange things began to happen. First, an ugly face appeared in the window, then a shot rang out ...
Learning about the misadventures of her friend, Lyuska began to get used to the role of a detective. The first thing to find out was that no one lives in the house for two years. But how then to explain the holiday arranged on Friday, the thirteenth?
For secondary and senior school age