The police are often called to come to places where suspicious things are happening. Risk is part of the job and some cases are not only very complicated, but also dangerous. Marta, Andrea and Roger are on duty today. They have been called by an anonymous person to go to a very secret property. There would be gatherings of people here at night with black cars. What are these people doing? Why do they gather every night? Our police officers are tasked with investigating the situation and trying to figure out what is going on. Help them to solve this case and find out what these strange people are doing.