The first two entries of 31 Days had light hearted elements in them. Now we're going straight to the jugular. The French have had a penchant for extreme violence in their latest entries into the horror genre. Instead of the machete they give us the concrete saw. With Inside, it is a multitude of weapons. The cold dead gaze of a crazed Beatrice Dalle being For my money, it the most succesful in developing overwhelming tension. Both Martyrs & High Tension had sharp left turns when they approached their third act. The former going to the point of changing the concept (a ballsy move rarely seen in horror) of the movie entirely.
When dealing with Inside, it's straight up tension until those last heart pounding minutes. Now I won't spoil it for you. But you'll know exactly when it comes. It's a constant one upmanship in terms of gore and grue that offers us the flip side of the coin to the zany antics Peter Jackson gave us in Dead Alive.