Movie submitted by Antonio:
A girl goes to an apartment of a building for a delivery.She is greeted by someone who soon disappears. When attempting to leave the door remains locked and can not get out. The place looks like a big half-empty hall, with large windows overlooking the outside. Strange events begin to occur: people who appear and disappear, murders of which soon no trace remains. It is extremely scared subject to threats of various kinds. Try to draw the attention of passers-by, but the place is located on a high floor of the building and the windows do not open.
Everything points to the presence of spirit entities or something. On the final but there is the twist. There is nothing paranormal, but everything had been meticulously studied (do not remember the reason, perhaps to eliminate someone to matters of inheritance).