Economical horror with a promising premise which delivers in part. A familiar almost Agatha Christie who-dun-it story is given a modern day setting with spiritual undertones.
The claustrophobic setting, sound effects and sharp editing create a succession of low-budget scares, although the turn of events become slightly repetitive each time the lights go out. The use of elevator CCTV footage provides some variety to the action and builds suspense as the audience are made to feel equally as helpless as the rescuers as they see the action play out in front of them.
A potential step back towards form for producer M. Night Shyamalan.