[spoiler]There is a creature the scientists nick named "Deadzone". It is an electric based beast and is capable of distorting space thus masking all signals or signs of life or powering out or on devices. This only happens when the creature is within 100ft. So you are good thus far and correct that at the bottom of the ninth floor there are signs of life. Beyond the door are no zombies, but a hella ton of monsters.[/spoiler]