Detective: The Crime of lord

Save yourself and humanity! It’s 1960s England and there's a beautiful 3-floor mansion in the shade of branchy trees. You've travelled for days to reach a castle hidden deep. With a friendly landlord and inexpensive rent, most people would envy those who live here. But bloody things are happening inside of this house. Guests are beheaded, and with every new victim humankind is getting closer to meeting a horrible monster. Is there anyone to prevent this nightmare?