Stefanie and Ulrike - Cousins ​​Part 1 of 7

Stefanie is waiting for her cousin. When the doorbell rings, a utility worker is at the door. Inside the apartment, he overpowers Stefanie and ties her up in the basement. Then he waits for Stefanie's cousin. Ulrike unlocks the door a short time later and is also overpowered. So, the two cousins ​​end up bound and gagged together in the basement. What does the stranger intend to do?