In a remote villa in the suburbs, the door to the basement slowly opened. The door didn't even make a small creaking sound which made the person inside not notice anything. This shows how smooth the hinges of the door are, which also shows that they are very new, as if they haven't been used for a short while. So, it wouldn't matter whether the door was opened how many times it is.
Anyway, it is not as if the newcomer not want to alert the person inside. Also, it is not as if the person inside the basement is not aware who the owner of the villa is. So, even if he doesn't know that the door to the basement opened, he is sure that it can only be the owner of the villa who arrived. After all, he knows that the owner of the villa wouldn't let any stranger intrude his place.
Also… there is an array here to keep the outsiders from entering, and also seeing what exactly is inside the villa.
