My Idea for a new horror movie

Premise; Cursed Nazi gold is brought back to a war museum in London where the curse begins to seep in to the building and its inhabitants. Bad luck becomes more frequent yet no one is quite sure of the cause. One evening, a night-watchmen goes missing. Believing he has simply forgotten to clock out, work continues as normal (or as normal as it can be with all the bad luck). A few days later, a small child notices one of the mannequin is slumping in an odd fashion, he approaches it only to discover a pool of blood by its feet, it turns out to be the body of the missing watchmen. Police are called to the scene and are at a loss as too what happened. That night, a police officer goes missing and a search is issued to find him, and they do. His body is found in a similar fashion to the other, dressed up and posed as a mannequin. The museum is placed under lockdown, nobody is allowed in or out, leaving six police investigators trapped in the museum looking for the killer. The power goes out and alone, in the dark and with no idea of the layout of the museum, the six must navigate their way through the maze of rooms and sets trying to hunt down the killer, all the while being separated and picked off one by one.