Okay, so I saw this movie about 5-7 years ago, definitely english, movie, and in color. Due to the fact I saw it a few years ago, I cannot remember the exact plot, but I think it’s about a teenage girl and her brother stuck in a house while people that are either trying to steal from the house or use them for ransom. I think their father was quite rich and the house had cameras everywhere and other things. A part I distinctly remember is when the girl was in her bedroom with one of the intruders and she cut his neck, leaving the veiwer to assume that she killed him. You find out later that he is, in fact, alive when she locks herself in a room with her brother that has a two-way mirror and he writes something on the glass in his own blood, which I do not remember what. Any help would be GREATLY appreciated, becuase the name of this movie has puzzled me for years.